So sacrificed a pawn twice, the first to break Zhou’s queenside pawn structure and the second to launch a kingside pawn attack that netted him a piece for two pawns. He pressed on his charge and was on his way to gobbling up two of his rival’s scattered pawns when Zhou resigned.
With the victory, the top-seeded So took a one-point lead over another Chinese, second pick Bu Xiangzhi, and No. 3 Timur Gareyev, who had five points apiece.
Bu trounced Becerra in 53 moves of a Slav duel while Yermolinsky bounced back from a fourth round defeat to So with a shock 60-move triumph over No. 3 Timur Gareyev of a Queen’s Pawn game.
In six games, So has gained 10.5 rating points to set a career-best 2772.5 live rating, good for No. 10 in the world but closer to No. 9 Hiraku Nakamura of the US with 2777.1.
In the fifth round, So stunned American GM Sergey Erenburg with a brilliant 49-move win of a super-sharp French encounter.
After keeping a pair of bishops following a series of tactical exchanges,
So gave up a pawn on the 36th move to expose Erenburg’s king at center before giving up a bishop on an empty space to trap the latter’s queen.
The nine-round, five-day tournament staking $10,000 serves as part of So’s buildup for the tough Tata Steel Masters set Jan. 9 in The Netherlands.