Late goals from Aston Villa duo Stiliyan Petrov and Darren Bent heaped more pressure on Chelsea manager Andre Villas-Boas this afternoon.
All looked to be going well for hosts Chelsea when Didier Drogba put them in front.
As Drogba advanced into the penalty area he was upended by Richard Dunne in the 23rd minute. The Ivorian dusted himself down to dispatch the resultant spot-kick past Brad Guzan, despite the American guessing the right direction.
However, the home side's lead would only least for five minutes. Charles N'Zogbia was the creator for Villa, seeing his effort fall to Stephen Ireland, who converted from close range despite the efforts of Blues captain John Terry on the line.
Chelsea substitute Fernando Torres almost made an immediate impact after 62 minutes but his 30-yard effort cannoned away to safety of the crossbar.
The home side then had an appeal for a penalty turned down in the 74th minute when Marc Albrighton appeared to catch Chelsea full-back Ashley Cole high on the chest.
The all important third goal of the game came against the run of play in the 82nd minute courtesy of Villa skipper Petrov, who shot past Petr Cech following a counter-attack.
Another quick break four minutes later sealed the points for Villa when Ireland turned provider for Bent to score from close range. It was Bent's first away goal since May of this year.
The defeat has left Chelsea trailing leaders Manchester City by nine points, having also played one game more.
