Demba Ba's first-half goal proved to be enough to give Chelsea all three points and move them up to third spot in the table for 24 hours at least.
All eyes before kick-off were on Benitez to see what reception he would receive from the Chelsea fans at the start of the game, but apart from a few banners being erected around Stamford Bridge calling for the Spaniard's head the expected backlash was quite muted.
Chelsea made a bright start and really should have scored after just three minutes when Ba got down the right and picked out Oscar inside the box, but the Brazilian could only stab his shot into the ground allowing Ben Foster to scramble across his line to keep out his effort.
Three minutes later West Brom created their first chance of the game when defender Steven Reid forced Petr Cech to tip the ball over his crossbar with a fiercely struck free-kick from fully 35 yards.
Chelsea continued to call the tune and Oscar headed straight at Foster from Juan Mata's cross before Ba hit a left-footed effort down the throat of the West Brom 'keeper.
Foster, who was being watched by England boss Roy Hodgson, denied Chelsea the opener on 26 minutes when he reacted well to keep out David Luiz's deflected free-kick on the edge of the box.
Chelsea made the breakthrough just before the half hour mark with Ba netting his second Premier League goal for the club.
Frank Lampard worked a short corner to Oscar who whipped in a cross to the far post to David Luiz to head back across the face of goal for Ba to slot home from six yards out.
Chelsea continued to dominate proceedings in the second half and Ba almost got his second of the game on 55 minutes when the ball dropped to him inside the box from Oscar's corner, but Foster just about managed to scramble the ball away to safety.
Foster kept West Brom in the game on 79 minutes when he produced a smart save to keep out Oscar's volley after Ba had headed the ball down into the path of the Brazilian and minutes later Oscar was again denied by Foster with the keeper getting down low to keep out his shot inside the box.
West Brom substitute Peter Odemwingie forced Cech into a save seven minutes from time when he tipped his free-kick over the crossbar. From the resulting corner Cesar Azpilicueta almost headed into his own net, but Cech produced an instinctive save to keep the ball out as Chelsea held on for the win.