Alan Pardew blamed a lack of intensity for Newcastle United's 4-0 defeat to Wigan Athletic on Saturday.
Wigan were four to the good at half-time thanks to goals from Shaun Maloney, Franco Di Santo and a double from Victor Moses.
And although Pardew was happier with the second-half performance, he was disappointed with the sluggish start.
"We didn't match the intensity of Wigan," he told reporters.
"And in any Premier League game, that will make you look bad.
"We talked in the dressing room (before the game) about not being complacent and giving Wigan the respect they deserved, but we didn't get a grip of them in the first 30 minutes.
"We got caught out by that one word – intensity. But you have to say that Wigan were brilliant today and credit to Roberto (Martinez).
Pardew said he would not be dwelling on the defeat for long with the crucial match against Chelsea just four days away.
"We failed as a team, not as individuals. It is important that we go to Chelsea with an away game mentality, which we didn't do today. When you've won six on the trot you can go away and think 'we'll win today'.
"It will be a shock to the players. I am expecting a reaction on Wednesday."
Meanwhile, Wigan's Roberto Martinez has challenged his buoyant players to finish off the job of securing survival after moving closer to safety with the win.
"I'm extremely pleased because what we've shown is a real clinical touch that we have lacked in the past," Martinez said.
"I thought the 4-0 lead was fully deserved at half-time and there is a real satisfaction that we saw it through.
"It was huge win and we have two more huge games against Blackburn and Wolves. This result is fantastic for the fans but if we don't achieve our aim of staying in this league then it is going to mean nothing."
Martinez reserved particular praise for Moses.
"It is a joy to see how Victor is growing at this club. He is the sort of player you'd pay money to watch and that is down to his raw talent and the manner in which he has been working and understanding the game."