Assaidi's bolt from the blue shocks off-colour Chelsea
Stoke 3 Chelsea 2
A 90th-minute thunderbolt from Oussama Assaidi sealed a dramatic victory for Stoke over Chelsea. This frantic and tetchy encounter appeared to be heading for a draw until the Moroccan, on as a late substitute, hit a rasping drive from the edge of the area that had Petr Cech grasping for air.
Andre Schurrle had given Chelsea the lead with a long-range effort of his own, and from almost the exact position on 19 minutes, before Stoke scored twice either side of half-time with Peter Crouch and then Stephen Ireland striking in contrasting style.
Schurrle then struck again to cap the German's most effective display for the London club since his summer arrival from Bayer Leverkusen and it appeared Stoke's hopes of recording a first league win over Chelsea since 1975 had gone.
Then, however, came the winner, with Assaidi, who is on a season-long loan from Liverpool, letting fly from the left-edge of the visitors area after cutting across Bransilav Ivanovic and unleashing a right-footed drive that swerved away from Cech's reach. Chelsea were stunned and saw their chances of cutting the gap with leaders Arsenal blown apart.
The hosts started brightly, with Jonathan Walters and Marko Arnautovic looking to stretch Chelsea from out wide. The visitors were the more threatening and should have taken the lead on four minutes when Ramires hit an effort high over the bar.
Five minutes later, Schurrle capped an impressive start to proceedings with the opening goal, firing a low drive from the left-hand edge of the area, having collected John Obi Mikel's pass and taken advantage of some poor defending.
Things got worse for Stoke on 18 minutes when Charlie Adam went off injured. The top scorer was replaced by Ireland, with the midfielder coming into a side that was being outplayed by their opponents. Chelsea were dominating possession, with their attacking trio of Eden Hazard, Juan Mata and Schurrle causing havoc for the hosts.
The mood changed considerably three minutes from the break, however, when Stoke equalised. Arnautovic's corner from the left was not cleared by Chelsea and Crouch struck with a scrappy shot that went through the legs of Cech. The manner of the goal would have particularly annoyed Jose Mourinho, given his criticism of the way in which his side defended set-pieces against Sunderland.
Galvanised by the equaliser, the hosts dominated the early stages of the second half and were rewarded for their efforts when Ireland scored on 50 minutes with a brilliantly placed curling drive from just outside the Chelsea area.
Cue thunderous singing from the home support, but they were to be silenced shortly after when Schurrle struck to make it 2-2, drilling a long-range drive past Asmir Begovic after Crouch inadvertently cleared Mata's free-kick into the path of the 23-year-old. Schurrle then thought he had his hat-trick, only to see his curling effort clip the top of the bar.
With space opening up in an increasingly frantic contest, Steven Nzonzi found Crouch, who chested it into the path of the waiting Ireland, but the Irishman sent his shot sailing over the bar.
Frank Lampard was introduced on 70 minutes, coming on for Mikel while Schurrle was replaced by Samuel Eto'o. Chelsea were now lined-up in a 4-4-2 formation as the hunt for a third goal became increasingly desperate.
But Stoke continued to harass the visitors and Assaidi delivered the death blow with a stunning shot to seal the points.