The Blues open the scoring in the 20th minutes when debutant Pedro, scored his first Chelsea and Premiership goal after tapping in an Eden Hazard cross.
Fellow Spanish international Diego Costa, also increased the tally in the 30th minute making it two for the London club.
Jay Morrison pulled one back for the home team in the 35th minute, before Chelsea defender Azpillicuta added another goal in the 42nd minutes making it 3-1 in favour of Chelsea.
Back from recess, Captain John Terry was given the matching orders after referee mark Clattenburg showed him the red card on the 54th minute.
Jay Morrison who had earlier missed a penalty pulled another goal back for Westbrom in the 59th minute.
The game ended 3-2 after 90 minutes in favour of Chelsea.