Former world champion Veselin Topalov of Bulgaria caught Krishnan Sasikiran on the wrong foot and handed the Indian Grandmaster his first defeat of the tournament in the fourth round of the ongoing 3rd Mtel International Chess tournament in Sofia, Bulgaria.
Overnight joint second, Sasikiran slipped to the joint third place with six more rounds to go in the category-20 event.
Having played quite well so far to get two points out of a possible three, Sasikiran could not withstand Topalov's ingenious piece-play with the black.
In the other games of the round, Azerbaijan's Shakhriyar Mamedyarov drew with former European champion Liviu-Dieter Nisipeanu of Romania to remain in sole lead on three points.
Michael Adams, after his draw with American Gata Kamsky, is the sole second with 2.5 points, followed by the Sasikiran-Nisipeanu duo. Topalov is next in line a half point adrift, while Kamsky, with just one point, is at the bottom of the table.
It was also a revenge of sort for Topalov who had gone down to the Indian in the Chess Olympiad.
Playing black, Topalov employed the King's Indian defence and Sasikiran went for his pet Classical setup. Complexities ensued in the early middle game when Topalov went for grabbing queen side pawns with his queen and, at one point, Sasikiran completely missed the thread of the position to find the menacing black pawns marching down in his territory. The game lasted just 33 moves.