Guus Hiddink criticised his Chelsea players for switching off at White Hart Lane and missing their golden opportunity to close the gap in the Barclays Premier League title race.
Luka Modric's 50th-minute winner for Tottenham meant Hiddink's men failed to take advantage of Manchester United losing at Fulham, with the leaders maintaining their four-point advantage despite defeat at Craven Cottage.
"When you're chasing you have to win your games but to lose the goal as we did in the 10 minutes after half-time, with so many professionals and internationals, is bad for us," Hiddink said. "You have to know, when there is a fire in the kitchen, when to flood that fire."
Chelsea skipper John Terry forced a stunning save from Spurs goalkeeper Heurelho Gomes late on and Alex hit the crossbar in stoppage time, leaving Hiddink to reflect on the poor marking that allowed Modric to strike.
Aaron Lennon, with England boss Fabio Capello expected in the stands, cut the ball back from the right flank and Modric struck first time from the edge of the area past Petr Cech.
A suspect vehicle left near the stadium meant kick-off was delayed by 30 minutes, so Chelsea started the match knowing United were struggling at Fulham.
Hiddink added: "We lost a huge opportunity, knowing that United were losing, it was a great chance to really change things. But we missed it due to our start, especially in the second half.
"We talked about that at half-time, we knew they would come at us from the start and we emphasised that but it was very sloppy defending for their goal.
"The team finally woke up and we took over. We didn't control it but we couldn't and that was disappointing."
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