"It was an unbelievable atmosphere, the best I've ever played in", said Oxlade-Chamberlain, who struck a superb second goal in Liverpool's 3-0 victory.
Oxlade-Chamberlain and company will next take on Everton in the Merseyside derby on Saturday.
He claims Oxlade-Chamberlain in particular has been impressive since quitting the Emirates.
Liverpool have been charged by Uefa after the City team coach was damaged outside Anfield before kick-off but it was the noise inside that Oxlade-Chamberlain has cited as having the greater influence on the first leg.
"It was an fantastic atmosphere, the best I've ever played in", said the £40 million summer acquisition from Arsenal.
The Reds became the first team to record two victories over Pep Guardiola's Premier League leaders this term as goals from Mohamed Salah, Sadio Mane and Oxlade-Chamberlain handed Jurgen Klopp's men a commanding 3-0 lead in the quarter final tie.
Oxlade-Chamberlain said after the match that Klopp has been urging him to "take games by the scruff of the neck" and "make the difference".
Oxlade-Chamberlain signed for Arsenal six years ago and his progress at the club was often interrupted by injuries.
Wenger certainly can not be criticised for a lack of patience with his protege, having sat through his fair share of tortuous performances while supporting Oxlade-Chamberlain in the face of burgeoning criticism.
"Being in a different place can sometimes be better [but] only if you are aware of your problems".
The goal - I need to produce more moments like that. "It was always "I could do more" or 'I could have done something more".
'He never blamed Arsene Wenger for not improving enough, or whatever.
"Alex I would say has probably done slightly better out of the two".
No English footballer this year has turned his season and perhaps reputation around quicker than this midfielder; someone who arrived at Liverpool on the final day of the transfer window in August with many critics.
'He's an outstanding talent still, still a lot of things to improve, no problem with that'.
"That's what we were hoping for". "The further you go the better the teams you play against and you don't get many opportunities so you have to be clinical".