Harry Redknapp felt we gave as good as we got against City until Edin Dzeko's quickfire double before half-time left us chasing Sunday's Premier League encounter at the Lane.
Both goalkeepers made fine saves in the frantic early exchanges but the key moments arrived between the 35th and 41st minutes.
Edin Dzeko opened the scoring in the 35th minute and five minutes later, Peter Crouch was inches wide with a flying header from Gareth Bale's cross.
However, City broke up the other and and Dzeko was there again to head City into a 2-0 lead going into the break.
Tom Huddlestone replaced Niko Kranjcar at half-time and we then lost Aaron Lennon to injury before City ended the contest with Dzeko completing his hat-trick and Sergio Aguero on target in the 54th and 60th minutes.
Younes Kaboul powered home a header to restore some pride in the 68th minute but Dzeko had the final word by curling in his fourth for the final 5-1 scoreline.
"For 35 minutes there was nothing in the game, we had as many chances as they did," said Harry.
"We started the game brightly and had some good opportunities. We were right in the game, there were chances galore out there but we couldn't convert one.
"But then we didn't defend well enough, in all honesty. They played a push and run around the edge of our box, we didn't track and they scored, then a free header. We didn't defend well enough as a unit.
"That cost us and once you go a couple of goals behind against a good side like that, it's very difficult. They've got fantastic forward players and it will be difficult for anyone to contain them over 90 minutes.
"It was disappointing but I'm sure we'll turn it around. We'll be right in there at the end of the season, I've no doubts about that."
Meanwhile, Harry reported that Niko Kranjcar (groin), Aaron Lennon (groin) and Rafa van der Vaart (hamstring) all picked up injuries.