Chelsea's title-winning credentials took an almighty bashing at White Hart Lane tonight as the League leaders were humbled 5-3 by Spurs, and that despite taking the lead.
A Diego Costa tap-in on 18 minutes seemed to set Chelsea on to a customary three points at the home of their London rivals.
But then, the steering wheel came off the Chelsea boat and Chelsea were left floundering under the onslaught from the north London side which saw them race into a 4-1 lead, a result of terrible defending and sloppy tackling by the boys from west London.
Hazard gave the Blues' faithful some hope when he reduced the deficit on the hour only to see Spurs restore their three-goal advantage with 12 minutes left. John Terry's goal, on 86 minutes, did not offer any serious suggestion of a thrilling comeback.
The game started in a manner which suggested that goals were coming.
Neither side seemed content to dwell on the ball for too long during the opening stages of the Derby.
And the first effort on goal, on four minutes, fell to Nabil Bentaleb, but his 20-yarder went straight to Thiabaut Courtois.
An early blow for the home side saw Ryan Mason suffer a hamstring pull after challenging Cesar Azpilicueta. The midfielder was replaced with Mousa Dembele on 14 minutes.
But on 18 minutes, the league leaders took the lead. A long throw-out by Courtois found Eden Hazard on the right. The midfielder mined pas Danny Rose before arrowing a low right-footer past goalkeeper Hugo Lloris. But the ball bounced off the upright into the path of Oscar who sent the ball ball to the waiting Diego Costa who had the easiest of chances to tap the ball over the goal line.
The lead was extinguished by Spurs striker Harry Kane with 15 minutes of the half remaining. The striker collected the ball on the left and, unfettered, cut inside before letting fly with a daisy-cutter from 20-yards out which squeezed into the corner of Chelsea net, giving Thabaut no chance.
With two minutes from the break Danny Rose was on the spot to ram Spurs into the lead.
Nacer Chadli had broken the Chelsea offside trap and he slid the ball past Courtois. The ball bounced off the post and the left back was perfectly placed to steer the ball home to put the home side into the lead.
Worse was to follow for the Blues when Cahill tripped Kane in the penalty area.
Up stepped Andros Townend who flashed the spot kick past Courtois. It was the final kick of the half as Jose Mourinho stormed down the tunnel fuming.
The Chelsea boss replaced ineffectual Oscar with Willian during the break.
Hazard had a brilliant chance to reduced the deficit five minutes after the restart but he blasted a left-footer over the Spurs crossbar.
Things went from bad to worse for the Blues when they conceded a fourth three minutes later and it was that man Kane who did the damGe. Recovering the ball from Chadli, the young striker strode forward to the edge of the
Chelsea area before cooly bending the ball around Courtois and I to his left hand side corner of the net.
The goal-fest was not yet over and the Spurs faithful sounded less sure of themselves when on 60 minutes Chelsea snatched their number two on the counter attack. Hazard smacked a low left-footer past Lloris after winning the ball in midfield and reviewing it back after an expert one-two with Cesc Fabregas.Spurs boss Mauricio Pochettino brought on defensive midfielder Paulinho for wing man Townsend.
Mourinho was furious that his side wasn't given a penalty on 69 minutes when Hazard took a tumble in then penalty area under a challenge from Jan Vetonghen.
Speed merchant Mohamed Salah entered the fray with 19 minutes left on the clockas the Blues went in search of a third that would get them back into the game. And the almost got it through the right book of Azpilicueta,but Lloiris was equal to the task, parrying away the goal-bound shot.
Instead it was Sours, on 78 minutes, who struck next, with Chadli drilling home a smart right-footer from the edge of the Chelsea penalty area following a counter-attack.
Ramires flashed the ball across goal on 83 minutes.
With just four minutes left, skipper John Terry reduced the deficit by tucking home a third at the far post after Hazard and Branislav Ivanovic conspired to open up the Spurs defence allowing Terry the simplest of chances.
Incredibly, Fabregas smacked the post with a deft right-footer as the fourth official signalled five added minutes.
But this was not to be some heroic escape act. This was simply terrible, at best a bad day at the office, at worse, a signal that the Blues are struggling away from home.and that might prove catastrophic come the end of the season.
Teams: Spurs, Lloris, Walker, Rose, Vertonghen, Townsend, Kane, Fazio, Chadli, Eriksen, Mason, Bentaleb
Subs, Vorm, Chiriches, Paulinho, Soldado, Dembele, Stambouli, Davies
Chelsea, Courtois, Ivanovic,Fabregas, Oscar, Hazard, Costa, Matic, Willian, Cahill, Terry, Azpilicueta
Subs, Cech, Zouma, Ramires,Drogba, Mikel, Salah, Remy