Here is GM Hansen’s clutch rd9 Groningen win with a sharp Grunfeld.

Michalik,P (2508) – Hansen,Eric (2539)
Grunfeld Russian System 7…Nc6[D97]
Groningen Open A Groningen NED (9.4), 30.12.2012

Position 1
Black has a pawn and the queenside majority as compensation for the exchange. How should black respond to the 39.a3 challenge?

Black to Play