Chelsea lead West Ham United 1-0 at the break thanks to a strike from Eden Hazard at Upton Park.
The Hammers were the first team to threaten as Kevin Nolan found Cheikhou Kouyate on the edge of the area, but the midfielder failed to beat Thibaut Courtois with a drive from the edge of the box.
Jose Mourinho's men edged ahead when Ramires crossed from the right, and his delivery was pinpoint for Hazard as the Belgian guided his header from close range past Adrian.
West Ham almost got themselves level when Diafra Sakho managed to get free in the penalty area and he headed a powerful effort towards goal, but Courtois saved to turn the ball past the post.
