Arsenal FC mounted an unlikely comeback in the final quarter to fight back from two goals down against FC Barcelona and keep alive their chances of reaching the UEFA Champions League semi-finals in a pulsating contest.
The holders were at their scintillating best from the first minute, and only an inspired display from Manuel Almunia in the home goal kept the scoresheet blank at the break, only for Zlatan Ibrahimović to finally beat the goalkeeper with a fine chipped finish less than 60 seconds after half-time.
The same player doubled the advantage 13 minutes later but substitute Theo Walcott's 69th-minute effort brought the Gunners back into the contest. Five minutes from time they were level when Carles Puyol was sent off for bringing down Cesc Fàbregas, the Arsenal captain – who will miss next week's second leg after his booking here – making no mistake with the resulting penalty to level the tie.
Arsenal were buoyed by the inclusion of Fàbregas and William Gallas after injury, yet the home side were on the back foot from the first whistle and Almunia was quickly diving to his right to push away Sergio Busquets' first-time shot. That was only the beginning of the Arsenal goalkeeper's work, Almunia blocking Lionel Messi's shot with his left leg after a typically incisive run.
Barça kept coming, Ibrahimović shooting into the side-netting after racing through. Almunia then made two superb saves in quick succession from Ibrahimović and Xavi Hernández, Alex Song blocking Lionel Messi's volley on the line in a frantic passage of play. Bacary Sagna then headed over a goalbound shot from Pedro Rodríguez as the home team continued to chase shadows.
It was 21 minutes until Arsenal put together a move of note, Samir Nasri flashing a shot wide. Any momentum Arsenal were gathering was disrupted by injuries to Andrey Arshavin and Gallas, however, and the half ended on another negative note for Arsène Wenger's team with Fàbregas picking up the booking that rules him out of the second leg.
Less than 60 seconds after the restart Arsenal's night got even worse, Gerard Piqué playing a long ball for Ibrahimović to catch out the advancing Almunia with a perfectly judged chip from the angle.
Pedro came close to a second, and although Victor Valdés was called into action for the first time by Nicklas Bendtner's powerful header, instead Ibrahimović doubled Barcelona's money. Xavi's pass caught out the Arsenal defence and the Swedish striker thumped his shot past the exposed Almunia.
Wenger responded by replacing Sagna with Walcott and within three minutes the substitute had revived home hopes, sliding a shot under Valdés after good work from Nasri and Bendtner. Suddenly Barça found themselves under pressure, Piqué picking up a booking that also rules him out of the return, as Arsenal responded to exhortations to push forward.
That inevitably left extra space and Messi came close to exploiting it, only another fine Almunia stop denying the Argentinian. The home fans afforded Barcelona replacement Thierry Henry a generous reception on his introduction for Ibrahimović with 13 minutes remaining, and there was more to celebrate when Fàbregas was felled by Puyol, who was dismissed, the Arsenal captain smashing in the penalty despite having injured his leg.