Grandmaster Krishnan Sasikiran suffered a defeat at the hands of Ruslan Ponomariov of Ukraine in the first game of pre-quarterfinals at the chess World Cup in Khanty-Mansiysk (Russia [Images]).

Sasikiran, who had drawn all his classical games thus far in the event, found a tough customer in Ponomariov who played energetically to go one up in the two-games mini-match.

Sasikiran, the lone Indian left in the fray after the first round, now faces an ouster threat as he needs win the return game now to take the game to tiebreaker under which games of faster time control will be played.

For the record, if Sasikiran wins the return game, he will be needed to play in two games under rapid chess and if still tied the players will play two blitz games.

In case the deadlock continues, an Armageddon game will be played with white having six minutes against black's five but white must win.

Going for the Queen's Gambit Accepted did not prove a good choice for Sasikiran as Ponomariov established a slight advantage in the ensuing middle game.

The Ukrainian, who already came back from behind to win two earlier matches, displayed some fine attacking acumen while clubbing it with his positional skills at the same time.

Sasikiran was already in troubles by moves 25 when his king side and position in the center came under the scanner and called it a day after 41 moves.

Apart from Ponomariov, Norwegian super-talent Magnus Carlsen and Latvian born Spaniard Alexei Shirov were the other winners on day one of the pre quarterfinals while the remaining five games ended in draws.

Shirov played excellently to beat Vladimir Akopian of Armenia. The fact that his victory came with black pieces strongly favours him for a berth in the quarterfinals as in the return game he will play with the slightly unfavourable colour of the game.

Shirov was treat to watch when he was playing a pawn less endgame wherein he was able to increase his advantage with sheer simplicity thanks to potent weaknesses in Akopian's camp.

The fancied encounter between Gata Kamsky of United States and Russian Peter Svidler ended in a draw.

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