© PA Photos
The visiting League One outfit had the first meaningful effort of the game with eight minutes on the clock, but Adam Forshaw drilled a shot wide of the near post.
It took the hosting Blues some time to record a meaningful shot at goal, but when they did, they almost went in front. Oscar linked with Juan Mata to leave himself with just Simon Moore to beat, but he slipped in the action of shooting and the ball struck the woodwork.
Forshaw again tried his luck from distance in the 35th minute, but Petr Cech got down to hold the attacker's effort at the first attempt.
As the half drew to a close Marcello Trotta did beat Cech in the Chelsea goal, but the referee had already called play back for a foul earlier in the move.
Frank Lampard had the final chance of the half for Chelsea, but he failed to find the target from close range.