Chelsea were humiliated 4-2 at home by Manchester City with Craig Bellamy and Carlos Tevez both netting twice for the visitors, while the home side ended the game with nine men.
Chelsea had taken the lead through Frank Lampard and he scored their second in injury-time from the penalty spot.
Before kick-off Wayne Bridge walked straight past Blues skipper John Terry, ignoring the customary handshake following recent press reports about the Chelsea skipper's off-field activities.
But it was on the pitch where it really counted and stand-in left back Florent Malouda let fly with a rasping 25-yarder on 12 minutes which inched over Shay Given's crossbar.
City countered on 18 minutes with an Adam Johnson free-kick, but Henrique Hilario anticipated the flight of the ball and held comfortably.
Didier Drogba had a glorious chance to open the scoring on 26 minutes, but he headed over the top, before missing a sitter on 36 minutes scooping over the bar from six yards out.
Pressure told and Chelsea took the lead with three minutes to half-time. Joe Cole sent Lampard clear on the right and the England midfielder slotted home, placing the ball across the stranded Given.
But within two minutes, a quick breakaway saw Tevez race into the Chelsea area. He twisted Ricardo Carvalho into the ground before hitting a weak shot on goal which Hilario made a hash of, letting the ball drift past him.
Six minutes into the second half and Bellamy did what he does best. He outsprinted the Chelsea midfield and defence, before coolly slotting home a left-footer from a tight angle to put his side into the lead.
Carlo Ancelotti replaced Cole to a chorus of boos from the Chelsea fans on 60 minutes. Ancelotti then replaced centre-back Carvalho with Salomon Kalou with 20 minutes to go as the home side pushed for the equaliser.
Instead disaster struck for Chelsea. With 15 minutes left, Juliano Belletti upended Gareth Barry in the penalty area.
Referee Mike Dean sent off the defender and Tevez smashed home the spot-kick to double the visitors' lead.
Worse was to follow with Michael Ballack given a second yellow card for a foul on Tevez, as the league leaders' discipline disintegrated.
The humiliation was complete with three minutes remaining when Shaun Wright-Philips ran through the Chelsea rearguard before passing to Bellamy, who side-footed in his side's fourth goal.
In injury time Lampard replied from the spot after Barry fouled Daniel Sturridge, but the damage was already done for the Premier League leaders.