With the simple idea of 9 Bg2, winning the a7-pawn.

White enjoys a sound extra pawn.

Keeping the queens on for a while so as not to leave White with the two bishops in the endgame.

The game continued 1...Qxd4? 2.Bxd4 0-0-0 3.Kd2 Nd7 4.Bxg7 Nxc5 5.Rh1 and White had a long-term advantage.

After 2.Qxe5 Nxe5 White is tactically unable to maintain the bishop pair.

Thanks to his active queen and the unsafe location of White's king, Black has considerable counterplay.

Swapping pieces to reach an endgame where the weak pawns on c3 and a2 will speak in Black's favour.

A tempting recapture, but this just helps Black's plan.

Preferable was 2.Rxe5 Bd6 3.Re2, followed by Qf3, keeping the queens on the board.

3.Qb1 Bc5+ 4.Kg2 d4 with an initiative.