André Villas-Boas's first brush with the Champions League may have proved something of a slog but, in victory, there were clear positives upon which to cling. The theory that Chelsea did not sign an expensive goalscorer in January continues to be exposed as a myth, even if it is David Luiz rather than Fernando Torres. Perhaps it is the Spaniard's role that should be reassessed. This was his night to be provider.

Each of Chelsea's goals resulted from Torres's lay-offs here, Juan Mata making a point of stirring the crowd to recognise his compatriot's contribution to the second, deep into stoppage time. This club is still seeking evidence that their £50m was well spent earlier in the year and Torres will not be remotely satisfied as a slick supply line rather than finisher, but any hint of form is to be cherished at present. Too much of the striker's career at Stamford Bridge to date has been traumatic.

Perhaps he had been stirred into a more threatening display by the reminder of his responsibilities delivered by his manager prior to this tie, following comments allegedly made in an interview with the Spanish league's website. Whether Torres had indeed suggested his "older" club-mates had been "very slow" in their approach play, and by implication nullified his own impact since his move to London, is still open to debate, but the issue appears to have been resolved. "The problem is solved, the problem is solved," said Villas-Boas. "The investigation [into the validity of the quotes, not the legitimacy of the sentiment] is over.

"We had a chat and the situation is solved. You saw a player very involved, who put in a good performance, like the team. Hopefully these things won't arise in the group again. If they do, I, as manager, will resolve them." Those comments contrasted with the manager hailing his entire team's "excellent work", "excellent effort" and "tremendous possession". Torres may have scored only one goal in 23 appearances for this club, but he has offered a persuasive case to be included at Manchester United on Sunday, particularly given Didier Drogba's absence with a head injury.

This might have been an even more awkward occasion than it actually proved. Villas-Boas's selection, with Frank Lampard on the bench and John Terry in the stands, had hinted at risk, though the quality Chelsea did field proved sufficient both to weather Leverkusen's threat and eventually erode the Germans' resistance. The flurry of opportunities created by the visitors around the hour mark had the locals' nerves jangling, the returning Michael Ballack denied by Petr Cech, having burst through on to Andre Schürrle's pass. Schürrle himself might have scored moments later, but the goalkeeper reacted well again. In truth, those were rare moments of alarm created amid the visitors' industry. It needed a flash of real flair to prise the contest apart.

Chelsea would privately have wished that that magical moment had been conjured by Torres, but the excellent Bernd Leno had thwarted him before the break to suggest this would be another evening of toil for little personal reward. Rather, it was David Luiz who claimed the limelight. The £23.5m signing from Benfica had not featured for club or country since being hauled unceremoniously from the fray by Carlo Ancelotti at half-time at Old Trafford in early May, a show of dissent following the visitors' early concession that day having spoiled an otherwise promising start to his career at the club. There had been a thigh injury since, but this was a return to the fray. If his defending can be unnecessarily risky at times, his unpredictability is an attacking threat to be tapped.

The gallop upfield midway through the second half was trademark, the ball flitting from Florent Malouda to Torres before David Luiz curled the Spaniard's lay-off gloriously round Stefan Reinartz and into the corner. He has scored three goals in 13 appearances for the Londoners. Torres has one from 23. "It's not the first time this season that you've seen our centre-halves breaking through, driving on with the ball," said Villas-Boas. "It's something we're proud of: all of them have that natural technical ability."

The drive and determination was Torres's in stoppage time, the burst away from Reinartz splaying Bayer open, with the forward unselfishly squaring for Mata to finish. Chelsea could take heart from the displays mustered by the new arrival from Valencia, the clever Raul Meireles and the ever eager and bright Daniel Sturridge, who had forced Leno into two smart saves and offered bite up front.

All will presumably be involved at Old Trafford on Sunday, along with Lampard and Terry. "That will be a different kind of challenge altogether," said the manager. "We face United perhaps in their most tremendous moment of motivation, flair and style. But I think it provokes in us a good challenge. We will go there to try to win it. Let's see what happens."

As for Torres, however, Villas-Boas refused to confirm if the Spaniard's contribution here was enough to make the starting XI for Sunday. "I have to make a decision. We have another couple of days to train, and he will compete with the other four for that position. We have to take the best decision possible," said the Chelsea manager.