Arsène Wenger could barely contain his laughter after a match that threatened to be one of the most humiliating of his career transformed into one of his most extraordinary triumphs. His side recovered from an error-strewn opening period in which they collapsed to a 4-0 deficit against Reading to hit back with seven goals and prevail 7-5 after extra-time.

"We had a big party in the second half," quipped the Arsenal manager before remarking that the freakish scoreline was more familiar in tennis, joking "so that's the first set to us". The shocked Reading manager, Brian McDermott, meanwhile, lamented that "this feels like a funeral".

Wenger added: "We went from disaster to getting some pride because we came back in the second half with a decent performance." He also declared that although the League Cup is not one of his priorities for the season, the first-half display was so bad that immediate improvement became of paramount importance.

"It was not one of our priorities but had we gone out the way we could have gone out on the basis of the first half, that would not have been one of my proudest moments at the club so I'm very happy that we came back." Asked whether what transpired constituted one of his greatest victories, "It may be" was the Frenchman's reply.

"I didn't feel great when they made it 4-0," added Wenger with masterful understatement. His mood was matched by the travelling Arsenal fans, many of whom left the stadium in disgust and missed their team's comeback. Wenger said that those who stayed helped inspire the transformation. "I just thought what can I do about that and started to think about my half-time speech," said Wenger. "I felt sorry for our fans and I would like to give them credit tonight. A big part of them stayed behind and I am happy that we paid them back." And for those who left? "I give them less credit," he chirped.

"We were sloppy [in the first half] and the boss told us it wasn't good enough, it wasn't Arsenal," said Theo Walcott, "we showed everyone that we never give up."

McDermott struggled to find words to say to his team after what he termed the "worst defeat of my career".

Such a crazy game could be said to defy analysis but McDermott identified Walcott's first goal — the one that made it 4-1 on the stroke of half-time — as the turning point. "I wasn't happy at half-time," he explained. "That goal gave them impetus that we didn't need [them to have]. We totally dominated the first half and they scored a goal out of nothing. When you give good players an opportunity, they take it. I really wanted us to get a fifth goal to finish them off, which seems a ridiculous thing to think when you're 4-1 up. But we didn't play in the second half, what we did was kamikaze stuff.

"We were really, really good for the first 35 minutes … but then when you see what we did in the second 45 minutes, it was bizarre to say the least," continued McDermott. "When you consider that we were 4-0 up and who we were playing against and we end up drawing 4-4 [after 90 minutes], it's just embarrassing for us all." McDermott nonetheless felt that the match should have been over before Arsenal equalised: the referee had indicated a minimum of four minutes of additional time and Walcott drew the sides level in the sixth. "You can't get the times as wrong as that," he said.

McDermott has given the players two days off to recover from this ordeal. Seeking some positives amid the gloom, he noted that many of them have recovered from major set-backs before, notably when they lost the Championship play-off final in 2011. "In football you have massive disappointment, and I had one of them a couple of years ago with that play-off final but we managed to come back and win the league the year after that."

As for looking for positives from this game, McDermott says he may not be able to study the game too closely. "I may just throw the dvd in the bin." He may try to forget, but everyone who saw this amazing match will remember it for a long time. "I know, and that makes me feel worse," said McDermott.