1) Arsenal survive first five minutes to earn redemption

If Daniel Sturridge had not been in that infuriatingly scatty mood into which he sometimes slips, then Liverpool would have been 2-0 up within five minutes, bettering the explosive start they made when demolishing Arsenal at Anfield eight days ago, yet this was still a much improved performance by Arsène Wenger's men. Above all, and unlike at Anfield, they displayed the combative character that befits a team of their ambitions, bursting with energy and aggression (and sometimes even viciousness). They truly earned the right to play their part in a thrilling tie.

2) Sanogo makes a bright first start

Yaya Sanogo suffered so many injuries as a teenager that at one particularly low point he contemplated abandoning his football dreams to become a postman – and that was before he endured the back injury that sidelined him for months just after joining Arsenal. So it was heartening to see the 21-year-old deliver on his long-delayed first start in English football. This was a much higher level than he has ever played before but he did not look out of his depth and instead caused regular discomfort to Liverpool's defenders thanks to his power and mobility. At times his touch was uncharacteristically rough – perhaps owing to nerves and the unfamiliar intensity of proceedings – but he never hid and showed a capacity to adapt quickly, notably through his contribution to Arsenal's first goal. After hesitating when Mesut Özil provided him with a prime opportunity to shoot in the 12th minute, he did not make the same mistake in the 17th, when he took Özil's cross nicely on his chest and immediately lashed the ball towards goal. Alex Oxlade-Chamberlain adeptly converted the rebound off Steven Gerrard.

3) Should Özil have been rested ahead of Bayern on Wednesday?

If it was slightly surprising to see Özil start, bearing in mind that he has looked jaded in recent weeks and a showdown with Bayern Munich looms, then Wenger's decision may have been vindicated as the German produced an influential performance. He did nothing astounding but was involved in everything, knitting together Arsenal's moves with relentless deftness. Will the surge in confidence that this performance should give him prove more beneficial than a rest? We should find out on Wednesday.

4) Can Oxlade-Chamberlain seize Walcott's England spot?

Brendan Rodgers recently suggested that there is no better winger in England than Raheem Sterling. Here Oxlade-Chamberlain may just have alerted him to one. Both players are wonderful to watch, of course, and Sterling has a snazzier trove of tricks and even looks a little faster but for now Oxlade-Chamberlain trumps those assets with his superior decision-making. If Roy Hodgson reduces the dilemma over how to replace Theo Walcott at the World Cup down to a choice between this pair, then Oxlade-Chamberlain currently looks the safer bet even if his long-term future lies in central midfield. But England could do far worse than play both of them at the same time.

5) Did Howard Webb bottle it?

Oh Howard Webb! The man reputed to be England's wisest referee was five yards away from the action when Oxlade-Chamberlain clunked into Suárez to concede a seemingly obvious penalty. But Webb waved play on. Perish the thought that he lacked the bottle to award the away team a second spot kick in a matter of minutes, so instead we must assume he saw something that was not apparent from farther away – nor on TV replays. It would be fascinating to find out what. After that, not showing a second yellow card to Gerrard when the England captain mowed down Oxlade-Chamberlain in the 76th minute came as no surprise.