Chelsea missed a golden opportunity to cut the gap at the top of the Barclays Premier League as Luka Modric's solitary strike helped Tottenham inflict Guus Hiddink's first defeat since arriving in England.
A suspect vehicle near White Hart Lane delayed kick-off, meaning the visitors kicked off knowing leaders Manchester United were struggling at Fulham, but they failed to take advantage.
Victory would have taken them within a point of United but Hiddink's men were frustrated by a Tottenham side who have been transformed since Harry Redknapp's arrival five months ago, with Modric striking the winner just after the interval.
Spurs goalkeeper Heurelho Gomes also played a huge part in the victory, saving from John Terry late on when the away fans thought they were on level terms. Alex also hit the crossbar in stoppage time as Spurs held on.
Redknapp's men were relegation candidates when he took over in October but they are unbeaten in six league games and could be in with a shout for Europe.
On a personal level, Redknapp had not beaten Chelsea in a league game since 1999. More importantly, he feels his side could challenge the traditional top four in their next campaign.
The visitors, however, have still not recorded a win over one of their London rivals this season and their task was not made easier by Ricardo Carvalho picking up an ankle injury this week, meaning Alex deputised at centre-back.
Deco's hamstring problem meant Juliano Belletti came in on the right side of a midfield squeezed for space, especially when Spurs skipper Robbie Keane dropped back to help his team-mates.
Hiddink's men were predictably limited to long shots and Michael Essien, back from a serious injury, forced Gomes into a save which he gathered at the second attempt early on.
At the other end, Jermaine Jenas just cleared the angle of crossbar and near post with a fizzing drive.
The hosts got closer in the 18th minute after Alex failed to deal with a long punt forward, with Petr Cech required to beat away Keane's powerful volley.
Cech stopped Keane again after Vedran Corluka had raced down the right and pulled the ball back, although this effort was much closer to the Chelsea goalkeeper.
The visitors were being denied space on the ball, with Nicolas Anelka often dropping into midfield to get involved. That was how the France striker started the move that ended with the ball breaking to him on the edge of the area and Gomes saving at the near post.
Encouraged by Chelsea's limited chances, Spurs attempted to break forward. Cech claimed the ball when Keane cut in and had a shot blocked by Alex and the Chelsea goalkeeper also plucked the ball from under his crossbar from Ledley King's looping header.
King clattered Didier Drogba with his thigh while winning a header and the Chelsea striker looked dazed while receiving treatment and heading down the tunnel, the visitors seeing out the first half with 10 men.
Drogba was fit to start the second half but Chelsea were behind within five minutes of the restart.
Aaron Lennon received the ball on the right, feigned to go down the flank but instead he crossed early, between Ashley Cole and Frank Lampard.
Keane could have struck but Modric took control of the situation, crisply finishing from the edge of the area into the bottom corner for his fourth goal of the season.
He almost repeated the trick when he got on the end of another Lennon cross, but this time his effort lacked power.
Hiddink's response was to bring on Ricardo Quaresma for Belletti, moments before Lampard struck the frame of the goal with a header at the far post.
Gomes saved from Drogba at the near post and from Quaresma's long-range effort as Chelsea searched for the equaliser.
Drogba sliced another shot wide, with Hiddink's next move to bring on Florent Malouda for Essien.
Terry forced Gomes into his stunning full-stretch save, then King's block on Anelka was equally important. Alex hit the bar deep in injury-time with a header from a corner but Spurs held on.
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.
It was Hiddink's first defeat since being appointed as Chelsea boss until the
end of the season.
"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.''
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.''
Hiddink knows all about Gomes as he brought him to PSV Eindhoven from Brazil.
"Gomes made one world-class save, and that saved the game, but after that it was over. We had pressure but we were reacting to them,'' Hiddink said.
Spurs boss Harry Redknapp hailed the impact of Modric, who struggled at the start of the season but turned his campaign around following the arrival Redknapp in October.
"He's special and has amazing ability,'' Redknapp said. "He's not a lightweight either - I thought he was a bit of an Eyal Berkovic but he's physically stronger. He can mix it with the big boys and he's a top-class player.''
Spurs are three points off seventh place, which could earn a place in Europe.
"That's 18 points from nine games so we're playing as well as anyone,''
Redknapp fielded a weakened team when Spurs crashed out of Europe last month -
but the Spurs boss feels it is still worth qualifying despite the added
"It wasn't that I disrespected the UEFA Cup - we were in a relegation battle and the Carling Cup final,'' he said. "I had to prioritise, if we had been in the top half we would have gone for it. We'll go for it again this season so let's push on and try and get seventh. We need to start looking upwards.''