Christian Benteke's 19th Premier League goal of the season has Aston Villa ahead against Chelsea after 45 frantic minutes at Villa Park.
The tone for a fast-paced encounter was set after two minutes when Nathan Baker was cautioned for an over-zealous challenge on Juan Mata.
Villa looked dangerous in attack and made their bright start count to take the lead after 14 minutes.
Benteke was the architect, latching onto a pass from Yacouba Sylla to run at the Chelsea defence.
The Belgian striker left Gary Cahill in his wake to burst clear at the far post and beat Petr Cech with an assured finish from close range.
Fabian Delph then whistled a fierce strike just over the crossbar from 20 yards as Villa looked to press home their advantage.
Chelsea responded positively and went close to an equaliser as Brad Guzan kept out Demba Ba with a fine save from close range.
Guzan was at full stretch again before the break, tipping a Frank Lampard free kick onto the post before denying Mata from the rebound.
Benteke was booked before the break following an aerial tussle with Cesar Azpilicueta, with John Terry soon following for a late lunge on Sylla.
Just before the interval Chelsea were reduced to 10 men as Ramires was issued with a second yellow card for a high challenge on Gabriel Agbonlahor.