One weak punch was the sum of most of his first half before being well beaten by a superb Walcott finish. Could do little for Giroud's excellent header but saved well from the Frenchman later in the half, first from a left-foot volley before diverting a clever header wide.
Got forward to support Robson-Kanu when he could and looked sturdy in defence but had a tougher spell in the second half. That said, most of Arsenal's good play came from the Reading right.
Linked well with McCleary on the right touchline and delivered the teasing cross that forced Koscielny into his own goal. Was lucky to not concede a penalty as he handled when tracking Chamakh's run and his game went downhill from there, culminating in a terrible attempted backpass to hand Chamakh the chance to score the seventh.
Marshalled the back line well for the majority but was carved open by Arshavin's delightful through-ball for Arsenal's first goal. Likewise to Morrison, struggled up against the lively Giroud and lost Koscielny for Arsenal's third goal. Was nutmegged by Chamakh's goal.
Climbed well but saw his early header cannon back off the crossbar. Defensively, he could do little to prevent the first goal - Arshavin's pass was too precise and noticeably found the going tougher with Giroud's presence up front for Arsenal. Booked in extra time.
Sliced his way through the defence but was denied by a good stop by Martinez. Picked up the loose ball and fed Hunt in the build-up to the opener. Looked lively in the early stages but faded as the game went on.
His speculative drive from the edge of the box should never have troubled Martinez but the Argentine fluffed his lines, handing the midfielder his second goal in a week. He was competitive and reliable throughout, though booked for a late tackle on Eisfeld.
Started the game battling Djourou before eluding Koscielny in the box to tap home the opener. Gave both centre-backs a torrid time thanks to his physicality and determination, spearheading the attack impressively.
Delivered the perfect cross for Roberts to smash home the opener from out wide and was another to constantly worry the Arsenal back line. Faded as the game went on, however.
A neat one-two with Gunter set the full-back away who went onto create the second goal. Was a constant threat from the right and troubled Miquel throughout before being replaced by McAnuff with 17 to play.
Linked cleverly with Roberts and caused the Arsenal defence plenty of problems. The timing of his run allowed him to leap above Jenkinson for the fourth Reading goal and should have had a second-half penalty after a blatant push by Chamakh. Was replaced by Pogrebnyak with 17 minutes to play.
Was fortunate to see Morrison's header rebound off the post, his head and wide before reacting sharply to Tabb's run and spreading himself at his feet to make the save. His night deteriorated sharply though as first Roberts was unmarked for a simple tap-in, before he could only flap as Koscielny turned a cross past him. But worse was to come as his attempt to palm Leigertwood's shot wide backfired and looped over him and in for Reading's third. Could do little for the well-placed fourth. Was extremely unconvincing in the air all night.
One late challenge on McCleary aside, the Spaniard struggled to get close to the winger and watched on as he delivered the cross for Hunt's goal. Fortunate to see his interception nip over the bar rather than his own net. Suffered a dose of cramp and was replaced in the middle of extra time.
Had a tough battle with Roberts but perhaps should have closed Leigertwood down sooner. For a centre-back he was too often beaten in the air by smaller men. Had a couple of clumsy moments when challenging Roberts and later Pogrebnyak but looked more solid in the second period.
Beaten far too easily by Hunt for the fourth goal. His final ball was weak at the other end of the pitch but improved as the game went on. Was on hand to ensure Walcott's equaliser counted, volleying home the goal-line clearance.
The most experienced starter out there but he embodied the languid first half that saw the Gunners concede four. His own goal was a poorly directed interception and he completely lost Roberts for the opener. Was booked late on to compound a poor evening but did pop up in the 89th minute to make it 4-3 before escaping a second yellow card for a reckless challenge.
Didn't do his reputation justice as the Arsenal midfield were beaten on all fronts in the first half. Played a lovely ball over the top for Chamakh that should have led to a penalty and looked more composed as the game wore on.
Looked off the pace and understandably struggling with his match fitness. Did lash a decent volley just wide but didn't offer his defence enough protection in the first period and was replaced on the hour by Eisfeld.
His through-ball to Walcott was a reminder of the Russian's class after a relatively quiet half. Looked sprightly in the second period and gave Gunter much more to think about. Was a constant menace and powered into the box, firing a dangerous shot that led to Walcott's winner.
Lost the ball in midfield in the build-up to the first goal but showed glimpses of his talent, particularly on the stroke of half-time, jinking inside and striking a shot that was deflected wide. Watched his effort drift just wide in the second half before being replaced on the hour by Giroud.
Mustered Arsenal's first real shot on target but could only hit his left-footed effort straight at Federici. Largely anonymous in the first period and extremely fortunate not to concede a penalty for a reckless push on Hunt. Linked better with Giroud and fired through Gorkss' legs to make it 5-4. Made it 7-5 with a fantastic lobbed finish in the final seconds.
He has begged to play centrally and was given the chance here. Although his defence played absymally, Walcott continued to threaten with his pace and burst through on goal right on half-time before lifting a superb shot over Federici to give the Gunners hope. Touched a dangerous cross just wide of the far post before delivering a powerful corner for Giroud to score. Swung the late corner in for Koscielny's goal and then knocked the ball over the line to equalise in the 95th minute before scoring the winner, tapping home the rebound from Arshavin's effort. Everything he did had purpose and energy and without him Arsenal would have been dead and buried after half an hour.
On for McCleary with 17 to play but saw little of the ball as Reading defended for much of the remainder of the 90. Drove at the heart of the defence and struck a great shot across Martinez, forcing the keeper into a fine save. Claimed a late assist with his shot-cum-cross.
Entered play with 17 to go for Hunt and did his best to run the channels and eat up time. Drew fouls and did his job as an impact sub before popping up with five minutes to go to head McAnuff's cross-shot in.
Last minute sub for Roberts but did not impact on the game.
Came on in the 105th minute for Miquel to make his Arsenal debut.
On in the 62 minute for Frimpong and started to link play well from midfield. Struck one long-range effort well wide when a pass was the better option. However, his passing range was on display and he looked at home in midfield.
Came on in the 62nd minute for Gnabry and scored with his first touch, heading back across Federici to make it 4-2. Volleyed at goal before flicking another great header at goal, but was denied twice by Federici. Was everywhere and did all he could to inspire an Arsenal comeback, including laying the ball onto Chamakh for the fifth goal.