Peter Crouch again levelled the scores with a strike from close range .
It was the Blues who had the last say as William bagged his second of the game , before Diego Costa made sure of the result with their fourth in the 85th minute .
Peter Crouch again levelled the scores with a strike from close range , but it was the Blues who had the last say as William bagged his second of the game , before Diego Costa made sure of the result with their fourth in the 85th minute .