Topalov-Kasimdzhanov game four was a Bogo-Indian. Neither side seemed to have much of an advantage for most of the game, and when things simplified to a queen and knight endgame, it seemed a draw would result. Topalov played on, however, and managed to win a couple of pawns. In the end, though, Kasimdzhanov did manage to hold the draw with a perpetual check. This meant that rapid tie-breaks were required to decide the match. To the surprise of most, Kasimdzhanov won both games fairly quickly and went through to the final.