Thrilling final minutes at the DW Stadium, but sadly not the ending Latics wanted as Birmingham held on to claim all three points.
Charles N'Zogbia gave an inspirational performance and scored a superb opener, curling left-footed into the top corner to put his side ahead.
Roberto Martinez's men continued to control the first-half, and the game should really have been over by the half-way mark, as chances came, but were spurned. But credit to Birmingham, they got their act together for the second-period and pressed forward intent on getting back into the game with Sebastian Larsson playing a pivotal role.
Mike Pollitt, who replaced the injured Chris Kirkland early-on in the game, was unlucky to be on the receiving end of Birmingham's comeback, having made a number of fine saves during the game.
Jordi Gomez's first goal for the club put things on a knife-edge with moments to go, a precise left-footer from 20-yards out that left Joe Hart with no chance. Alas it was not enough…
The equaliser came on the hour-mark when Hendry Thomas was dubiously penalised for a foul on the left-wing. Larsson stepped up and curled one to the far post, bypassing every player in the box to creep in cruely.
Benitez then raced clear of the defence moments later to squeeze a shot past Pollitt that trickled into the net and put the visitors into the lead.
Frustration crept in as the home side tried desperately to get back into the game to no avail, Hendry Thomas will miss next weekend's trip to Stoke City after picking up his fifth yellow-card of the season.
Larsson capped things off with 20 minutes to go dispatching a free-kick into the bottom left-corner, and making sure the points were heading back down the M6.
