The Rosolimo Sicilian with Ivanchuk having prepared 8…Bh5 (instead of 8…Bf3 being the main line). 9.g4 was supposed to be better for white, according to GM Ioannis Papaioannou, but he quickly added “of course Topalov knows better”. The Bulgarian spent a lot of time in the opening, but it looks like he found a good way to put the black setup to test. White was slightly better until Ivanchuk decided not to recapture the pawn on e6. Immediately on the next move Topalov pushed e6-e7 and Black’s position collapsed. Read a report on the complete round at Chess Blog.

Topalov, Veselin (2793) – Ivanchuk, Vassily (2755)

Result: 1-0
Site: Thessaloniki
Date: 2013.05.25
[…] 1.e4 c5 2.¤f3 ¤c6 3.¥b5 d6 4.O-O ¥d7 5.¦e1 ¤f6 6.c3 a6 7.¥f1 ¥g4 8.h3 ¥h5 9.d4 ¥xf3 10.gxf3 cxd4 11.cxd4 d5 12.¤c3 e6 13.¥g5 ¥e7 14.¥xf6 ¥xf6 15.exd5 ¤xd4 16.¦e4 £b6 17.dxe6 £c5 18.e7 h5 19.¦c1 ¦h6 20.¢h1 ¦g6 21.¤e2