Stokeequalised froma well-flightedJermaine Pennantfree-kick that Gordonshould have cleared, buthehesitated, Carew got to the ball first, and Huth forced the ball over the line.
The double strike killed off the match as a competitive spectacle, although JermainePennant flashed in a couple of long-range free-kicks to give Birmingham some hope.
Asamoah Gyan regained the lead for Sunderland after the break, but the visitors sat back and finally buckled under a barrage of long throws and set-pieces, as two JermainePennant free-kicks set up Huth to score twice in the last seven minutes and seal a remarkable recovery.