Report and pics of Chelsea 3 Aston Villa 0

The Spanish striker scored one and helped create another, as the visiting claret and blues struggled to contain the Premier League title favourites.

Villa began the day in third, three points behind the top of the table home side, but they had absolutely no answer to Costa with Oscar also doing damage.

The latter broke the deadlock with just seven minutes on the clock at Stamford Bridge, after Branislav Ivanovic freed Willian down the right.

His shot was batted away by goalkeeper Brad Guzan but, when the rebound fell back to him, he tapped it across for Oscar to slot home.

A series of contested decisions saw Villa manager Paul Lambert and assistant Roy Keane swap death stares with Chelsea chief Jose Mourinho. The three would clash for most of the afternoon.

But it was the Blues gaffer who had the last laugh when his side suddenly sprang into life after the break, with a one-two between Eden Hazard and Willian.

The latter released Cesar Azpilicueta, who looked up to ping a pin-point cross into the path of Costa, who applied the finishing touch in the box.

It was game over when a move started by Cesc Fabregas saw him nudge the ball through to Costa, who left Philippe Senderos all at sea with tricky feet before going for goal.

Guzan watched his shot and acted but, again, couldn't hold the ball after making the save with Willian the benefactor this time, bundling the ball in on a good day at the office for Chelsea.

Clear-cut opportunities at goal had been few and far between for Villa, who found themselves well beaten by the finish.

Fabian Delph twice tried his luck from 25 yards out but missing the woodwork, while Nathan Baker headed on to the roof of the net from Ashley Westwood's free-kick.