Vachier-Lagrave - Dominguez 1/2This match saw Breyer Ruy Lopez, which became very popular in the recent years and is regular choice of the world champion Magnus Carlsen.
Black's position looked a bit shaky in the middlegame, but somehow he was holding in all lines.
Dominguez didn't like the look of 23...hxg5 24. exf6 Bxf6 25.Qf2 Nd7 26.e5, but post-mortem analysis proved that black is staying intact.
28.Rae1 was played to prevent ...Be5, to which would follow the quite dangerous 29.Rxe5 dxe5 30.d6.
Different attempts, like 34.Rxd6 Rxb2 35.Rxe6 Rxe6 36.Bd5 Rbe2 would also lead to a draw, which anyway was the final outcome on move 40.
Tomashevsky - Grischuk 1-0Another mind-boggling game with Grischuk as co-star. He played a novel idea (10...c6) in the King's Indian defence, but then spent around one hour on the next couple of moves.
Accepting the pawn 11.dxc6 Ndc5 was too dangerous, so Tomashevsky decided to follow the regular plans. At one point he changed his mind and retreated the queen back to square one (15.Qd1), but this was not an offer to repeat the moves, rather he was "preventing a5-a4 and checking what black was actually doing".
The principled continuation was 15.h4 a4 (15...Qxh4 16.g5 with 17.Rh1) 16. h5 Bd7 17.Qh3 cxd5 18.cxd5 b5 19.Rh1. Exactly this was the line that was bothering Sasha, forcing him to spend lots of time to find the antidote.
Tomashevsky sacrificed an exchange and gradually pushed black pieces into corner. The position was difficult to evaluate, but certainly much more easier to play with white.
Grischuk never managed to bring his forces back into game, and coupled with a terrible zeitnot, his game simply collapsed. Later he checked the engines and saw that 28...Qe7 29.Nb6 Nc7 was better, leading to a "totally crazy position".
Andreikin - Mamedyarov 0-1The game started quietly, as Exchange variation of the Slav defence. Black had the option to immediately push 9...c5, but he delayed it for one move.
The subtle difference, which Andreikin admitted missing, was that 12...0-0 is possible because 13.Nxd5 fails to 13...Ne4! and the queen is attacked. He expected only 12...Bd6 which runs into the crushing 13.Bb5+.
The game sharpened when white doubled black's f-pawns and pushed e4. Mamedyarov pointed that 18...dxc3 19.Rxc3 fxe5 20.Rg3+ Kf8 21.Qxd7 Qd6 would probably end up completely equal. He expected 19.exf6 Bxf6 20.Ne4 Bg7 when black is very comfortable, but he missed that 19.Bd3 dxc3 20.Qh6 f5 breaks against 21.Bxf5.
Andreikin erred with 25.Qe3, which allowed black to snatch the b2-pawn when the intended 26.Ng6+ and 27.Qxg5 was also dropping the e5-pawn.
Black proceeded to efficiently convert the advantage in the rook ending.