The brilliant Rg2!

This position arises from a game between Yeap Eng Chiam as black and Thong Yung Chen as white in the last round of KASUGI. Yeap Eng Chiam brilliantly played Rg2! On first sight, many would have thought it is a blunder, even Eng Chiam himself was surprised for a second after playing this move. But it turned out to be the winning move. Did you see the continuation after Qxg2?