Tactic : Black to Play

From a recent game. 

Black to play. 

Black to play

I almost found the correct line, but under time pressure missed the killer move, and faded into an advantage for Black, rather than a win.

Fully correct is [27...Re3 28. Qg4 Ne5 29. Nd2 Nxd3 30. Kg1 Qxf4 31. Qxf4 Nxf4 32. Rf1 Nd3 ] 

I played [ 27...Re3 28. Q5 Qxg5 29. Bxg5 Rxd3 30. b4 cb 31.ab a6 32.b5 Nb4 33. Bd2 ] where I could still have been much better, but I wasn't :)

Highlight between the brackets to see the moves...