Joleon Lescott has admitted Manchester City shot themselves in the foot in the derby.
Manchester United sealed a 4-3 victory at Old Trafford thanks to Michael Owen's controversial stoppage-time winner.
It was hard for City to take after they had clawed their way back into the game three times through two Craig Bellamy goals and one from Gareth Barry.
However former Everton defender Lescott was disappointed that Darren Fletcher scored with two free headers after Wayne Rooney had made the breakthrough.
While manager Mark Hughes complained about the time added on, Lescott said: "There are no excuses.
"We are pros and have to look at ourselves collectively and as individuals and realise that it just wasn't good enough.
"You're disappointed to lose any game - Craig scored two wonder goals for us and we thought we'd done enough to get a point, but it wasn't to be.
"We look at each other and we've made mistakes. We started the season with four clean sheets and now we've conceded goals. We have to correct that.
"Last-minute goals are hard to take. We are gutted to lose as we did. Maybe we showed a bit of naivety towards the end.
"We're not a side to sit back. We want to win every game but sometimes you have to realise you can't.
"You can't come to Old Trafford, concede four goals, and expect to get anything. We'll have to work on that in the week."
Lescott maintains they can trouble the top four and push for trophies this season.
"We knew the character was there," he told www.mancity.co.uk. "It's the first time this season we've gone behind and we've proved that we can come back and get ourselves in contention.
"Their fans didn't go home thinking it was an easy game. We put them under a lot of pressure. If we'd got the draw it would have been fully deserved.
"We believe in ourselves and we believe that we can push for honours this season. Arsenal came here and lost too. We still believe we can finish in the top four."
City are back in action on Wednesday when they face Fulham in the Carling Cup.
Lescott added: "It's good we have a chance to put things right. It would have been hard to wait another eight days until the West Ham game."
It was hard for City to take after they had clawed their way back into the game three times through two Craig Bellamy goals and one from Gareth Barry.
However former Everton defender Lescott was disappointed that Darren Fletcher scored with two free headers after Wayne Rooney had made the breakthrough.
While manager Mark Hughes complained about the time added on, Lescott said: "There are no excuses.
"We are pros and have to look at ourselves collectively and as individuals and realise that it just wasn't good enough.
"You're disappointed to lose any game - Craig scored two wonder goals for us and we thought we'd done enough to get a point, but it wasn't to be.
"We look at each other and we've made mistakes. We started the season with four clean sheets and now we've conceded goals. We have to correct that.
"Last-minute goals are hard to take. We are gutted to lose as we did. Maybe we showed a bit of naivety towards the end.
"We're not a side to sit back. We want to win every game but sometimes you have to realise you can't.
"You can't come to Old Trafford, concede four goals, and expect to get anything. We'll have to work on that in the week."
Lescott maintains they can trouble the top four and push for trophies this season.
"We knew the character was there," he told www.mancity.co.uk. "It's the first time this season we've gone behind and we've proved that we can come back and get ourselves in contention.
"Their fans didn't go home thinking it was an easy game. We put them under a lot of pressure. If we'd got the draw it would have been fully deserved.
"We believe in ourselves and we believe that we can push for honours this season. Arsenal came here and lost too. We still believe we can finish in the top four."
City are back in action on Wednesday when they face Fulham in the Carling Cup.
Lescott added: "It's good we have a chance to put things right. It would have been hard to wait another eight days until the West Ham game."
Copyright (c) Press Association
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