Full-time: Arsenal keep a rare clean sheet but failed to penetrate a Marseille team who defended very well and regularly, in the first half at least, threatened on the counter. The game fairly petered out in the second half after a promising opening but both sides' remain well placed to go through. Must have been the humidity. Bye.
90+2 min: After Vermaelen's freekick from 25 yards cannons off the wall, Song slips the ball wide to Van Persie, who whips in a superb cross. Morel's clearance is equally good.
90 min: There will be three minutes' detention.
88 min: After neat, incisive work by Arshavin, Van Persie is caught dawdling on the ball. It's not happening for Arsenal in what has been a disappointing second-half from them and a good defensive one from the visitors.
86 min: Corner for Arsenal. Areteta takes. Mandanda punches clear.
85 min: Feared hatchetman Rosciky cops a booking for an over-zealous tackle on Diarra.
83 min: Marseille change: J Ayew off, Gignac on. "I'm not sure if I'm pleasantly surprised that the Marseille players are (Shock!) not rolling around on the floor after being fouled, but are (Horror!) getting straight back to their feet and getting on with the game, or so depressed at the state of modern football that I've thought it worthy of comment," barfs Stuart Macnab, who does not say whether he is surprised that Arsenal players are not rolling around on the floor either.
80 min: Maybe Marseille aren't settling for a draw after all? They've still got some some forward momentum, and Fanni has just delivered a dine cross for A Ayew, who nuts wide from 10 yards. Moments layer Amalifitano, who has made a difference since coming on, fires low and wide from the right.
77 min: Delivery a metaphorical dig in the belly of Ben Dunn, Rosicky dissects Marseille's defence with a marvellous pass from midfield. Van Persie is clean through on goal! This is what the crowd have been waiting for! This is the moment where the in-form striker will sent his reputation blazing still further! This is ... oh, he's just plopped a half-arsed lob straight into the keeper's arms.
76 min: Wenger has grown tired of waiting for Gervinho to crown his promising build-up play, so throws on Arshavin instead.
75 min: Freekick to Marseille wide on the right after Arteta pushes over Amalifitano. Song clears. "Glad to see Rosicky on for Ramsey," hurrahs Ben Dunn. "The Arsenal midfield had been crying out for an urgent injection of Mmm, yeah, whatever."
73 min: Marseille substitution: Lucho on for Valbuena.
71 min: The game is starting to stagnate, as Marseille begin to settle for the point that would leave them well placed to go through, what with a home game against Olympiakos to come. Van Persie's introduction has yet to raise Arsenal's performance to a level where penetration looks more likely.
68 min: Marseille change: Rémy off, Amalfitano on.
66 min: Arsenal sub: ramsey off, Rosicky on.
64 min: Gervinho seems a nearly man. He is nearly playing very well. But he keeps undoing good work with clumsy conclusions. Just now, for example, he undid Song's nice build-up play and his own darting run by chesting the ball down to a defender rather than himself, thus spurning the shooting opportunity from 12 yards.
62 min: To tremendous acclaim, Van Persie enters the fray at the expense of Park. "Gervinho, although doing well, is not providing enough good balls for Park," blasts Diane Park, who may or may not be related to the Korean striker. "He is losing balls in the final third and missing the crucial pass. Park, I think, is not as involved because he hasn't really had that many games to gel with the first team..." That is is surely a factor and he certainly shouldn't be written off on the basis of one quiet performance (especially as he did well against Bolton) but it is not completely his team-mates' fault that he weighed lightly on this game: his movement was (understandably) out of synch with the rest of the team and his touch has been poor, betraying, perhaps, over-eagerness or nerves.
58 min: Valbuena's nimbleness becomes tiresome for Song, who shoves him to the ground. The ensuing freekick from the right provokes discomfort in the Arsenal defence but there were not enough Marseille bodies in the box to take advantage and Szcsesny tidies up.
57 min: Strong defending by Diawara to usher Gervinho off the ball after Song had released him with a fine pass from deep.
55 min: Arsenal are attacking in greater numbers, with Vermaelen frequently joining in. But Marseille are keeping them at bay at the moment.
53 min: Ayew skips past Song and cracks a low shot wide from 23 yards. "Am I the only Arsenal supporter that thinks that in wide shots, Mertesacker is easily confused with Bendtner?" wonders Adam Large. "Sometimes when the camera pans back to him, I have this reflexive feeling of annoyance, until I remember that the Bendy Bus is now in Sunderland."
50 min: Van Persie is warming up. Surely it is Park who will make way. He hasn't been able to get into the game at all.
47 min: Diarra brings down Song mid-way inside the the OM half. "Nine times out of a hundred a player would be booked for that," opines Sky's Alan Smith without showing his calculations. Arteta curls in the freekick, Mertesacker loops a header towards goal and Vermaelen tries to help it on into the net but Mandanda flaps it away.
46 min: Because OM kicked off in the first period, Arsenal do so this time. Fair's fair. "Do you think that the rising humidity in London has an impact on the quality of the MBM submissions from your readers?" drones Tim Smith. "If so, what is the impact?" I fear that the humidity has soared to such levels that rivers of sweat are coursing down readers' arms and onto their keyboards, frazzling their computers and sabotaging the dispatch of quality emails.
Half-time: No goals but an interesting and fun game, roughly eight times better than the one between these sides at the Vélodrome. Difficult to see it ending scoreless, especially with Van Persie's arrival looming ...
42 min: A loose ball in the middle pops out to Ramsey, who suddenly finds himself scampering towards goal from 40 yards out. However, he doesn't have the pace to fend off the back-tracking defenders so tries to pass to Park, but the pass is mislaid.
40 min: After a driving run by Ramsey, the Welshman is chopped down by Diarra, who gets a booking while Arsenal get a freekick in a very inviting position, ie about four yards outside the box and central. Arteta territory, surely. Bah! He sends in a drab effort that trundles apologetically wide.
36 min: This game is being played a frantic pace. It's all fractionally too much at the moment for Park, who, despite his willingness, seems just a tad out of tune with proceedings, though that may well be down to nerves and a lack of familiarity with his team-mates as much as the speed of the game.
34 min: A cop-out of a shot from Diarra. He couldn't decide who to pass to, so shuffled awkwardly and banged off a shot from 40 yards. With predictable consequences. High and wide it goes.
31 min: Gervinho is involved in almost everything good that Arsenal too - although, frustratingly, he has a tendency to goof with the final ball/decision: not so a moment ago, however, as he darted towards the box and then slipped a good ball wide to Ramsey, who had a clear sight of goal from 14 yards, but feinted before attempting to send a sidefooted shot to the keeper's left, but Diawara manages to block.
29 min: Bang! Gervinho opens fire from the edge of the area - with a rare example of an Arsenal player taking a keeper by surprise with a quick early shot - but Mandanda reacted fast enough to beat it away. Walcott collected the rebound but showed none of Gervinho's decisiveness and passed inside instead of shooting from 14 yards, to the dismay of Arsenal fans.
27 min: That, I believe, is what professionals call top, top play. At least it was right up to the bit where Gervinho mis-controlled just as a shooting opportunity materialised, but the build-up between him and Ramsey had been splendid.
24 min: This really is an engrossing, finely-poised game. Arsenal have enjoyed a lot more possession in the last 10 minutes than they did in the opening part of the game but Marseille remain menacing on the counter and their rapid one-twos keep catching out the full-backs. Rémy has just gone close following another such exchange.
21 min: Per Mertesacker may well be the defensive Peter Crouch. He really isn't as good in the air as his size suggests he should be (but he's good on the ground). And he deepens that impression by nodding the ball straight to a Marseille player (possibly Rémy) just now. Szcsesny saves the 23.5 yard shot. Arsenal then tear down the other end and Walcott rams a shot over the bar after a run and cross from Andre Santos.
19 min: After some good pressing, followed by snappy interplay twixt Gervinho, Walcott and Park, the ball trickles out of play and Marseille can relieve the pressure. But pressure there indeed was, as Arsenal have now got the upper hand in this game.
16 min: Gervinho again receives the ball in a central position some 40 yards from goal and turns and sprints at the defence. He eventually rifles a decent long-range at Mandanda, which the keeper holds without ado.
14 min: After OM' blistering start, Arsenal have got more to grips with the game and it's now quite even, although Marseille remain determined to find holes behind the full-backs but their passing in the last few minutes has not matched their ambition. "Dropping Koscielny seems a bit harsh, given that he's been our best defender recently," blurts Paul McElroy justly, although it could be that Koscielny is merely being rested - having said that, isn't it nice that Arsenal now have genuinely good alternatives in that position. "Also I'm no physicist but doesn't the ball move more predictably in lower humidity? Hence the stat." It must have been about 100% humidity at Stamford Bridge on Saturday.
11 min: Andre Santos hurtles down the left and his cross is handled by Diawara, giving Arsenal a free-kick from a good crossing position (angle too acute to shoot). Arteta drifts it in, N'koulou nuts it away. "I assume the officially 'clear night' will be used against Wenger when he doesn't see Song scissor kicking someone," chirps Zach Neeley. "But they should be careful about it boomeranging on them given how often important things don't make it into referees' reports."
9 min: Arsenal threaten for the first time, as Gervinho collects the ball in midfield and dashes forward before offloading to Walcott. The winger's shot is low and true, forcing Mandanda to plunge to his right to push it behind for a corner, which is cleared.
8 min: Arsenal are struggling to cope with Marseille's energy and slickness at the moment. And they seem taken aback at the sheer effrontery of the visitors. Andre Santos has jsut been robbed in his own territory, and Rémy almost made off with a goal but fired inches over from the corner of the box.
5 min: Danger for Arsenal! Jenkinson is exposed by an elementary one-two before Rémy crosses low and hard top the near post, where A Ayew gets the jump on Vermaelen and pokes the ball just wide from seven yards.
3 min: It's an engaging open start, with OM showing plenty of enterprise. They ripped forward very rapidly just now after Diawara stormed forward and fed J Ayew, but Vermaelen intervened to dispossess Valbuena. "I'm looking forward to the Arsenal game, for various reasons," confides George Solomons. "We will see how this really quite expensive signing Park gets on leading the line for the first XI; Walcott seems to be hitting form and I always like watching Walcott in good form; Arsenal seem to have a swagger back and that's always a good thing to watch too. But, crucially, I'm very interested to see how the humidity, at 77%, affects the game. I'm also very interested to know why we were told this stat underneath the team news and what on earth it means?" You were told it because it's one of the stats that Uefa pass on to journos, possibly because they think it's relevant but more probably because they want to show off that they're on top of things. They also tell us - officially! - that it's a "a clear night".
1 min: Tricky start from A Ayew as he zigs and zags his way down the left and then fires in a low cross that Rémy tries to flip into the net with panache. Mission failed.
1 min: No shocks here as the game begins with a kick-off, as per the convention.
7:43pm: Out lollop the teams, Marseille clad in a shiny turquoise kit that looks a lot like used Christmas wrapping paper.
Are Arsenal still in crisis? Is Arsene Wenger still a stubborn, washed-up, idealistic old fool? It's hard to keep up with what the learned folks are saying. What we know for sure is that if Arsenal win tonight, they're into the Champions League knock-out stages (for the last time in the foreseeable future, say the same people who didn't even think they would make it through this time). And look! Wenger's feeling confident enough to omit sizzling striker Robin Van Persie from his starting line-up. In comes Park Ju-Young instead, and it's a move that makes sense, both because it will help avoid the on-fire Dutchman from burning out, and because the Korean has a fine record of scoring against French team and put in an impressive performance against Bolton last week, where his movement, strength and finishing all looked very promising and leads one to suspect that Marouane Chamakh can look forward to a loan move to Sunderland some time soon. On the evidence of the match against Bolton, one obvious area where Park needs to improve is his understanding of the offside law, which is Darren Bent-esque. And his touch at times looked unsure, though nerves and adaptation were surely factors there.
There were rumblings in the French media today to the effect that Didier Deschamps, having sussed that Arsenal are still vulnerable defensively, was going to go with a gung-ho 4-4-2 and he may have done so, with Rémy and Jordan Ayew seeking to show up Arsenal's centrebacks' lack of speed. However, it could also be a 4-3-3 aimed at exposing Arsenal's iffy full-backs, whom the Ayew brothers have the wherewithal to get them in a right tizzy. Or a 4-5-1 aimed at securing a point. We'll see.
Arsenal: Szczesny; Jenkinson, Mertesacker, Vermaelen, André Santos; Song, Arteta; Walcott, Ramsey, Gervinho; Park
Subs: Fabianksi, Koscielny, Rosicky, Van Persie, Djourou, Arshavin, Benayoun
OM: Mandanda; Fanni, Diawara, N'Koulou, Morel; A Ayew, Diarra, Cheyrou, Valbuena; J Ayew, Rémy
Sub: Bracigliano, Azpilicueta, Gonzalez, Gignac, Traoré, Kaboré, Amalfitano
Ref: P Tagliavento