Indian Grandmaster B Adhiban went down to Hikaru Nakamura of United States in the first game of the third round of World Chess Cup here.
The loss as white came as a huge blow as Adhiban will now have to play for a victory with black pieces in the return game to stay in the match. The last remaining Indian will otherwise be ousted from the knockout event.
On a day of big upsets, Evgeny Tomashevsky of Russia caused the biggest reversal accounting for top seed Levon Aronian of Armenia. Tomashevsky won with black pieces and now needs just a draw in the return game as white to proceed to the pre-quarterfinals.
Alexander Grischuk was the other big name who struggled with his form and lost to Le Quang Liem, the only other Asian besides Adhiban.
Going for the Ruy Lopez exchange as black, Adhiban showed peaceful intentions with his white pieces that did not prove good. In the preceding games as white, aggression was the key factor behind Adhiban's success but this time he chose an endgame that is proven equal at top level chess.
The queen-less middle game required a lot of precision from Nakamura but he kept himself in the hunt by opting to retain the other pieces on the board.
Adhiban erred and lost a pawn on the 30th move and Nakamura wrapped the issue 12 moves later.
Aronian was shocked in a Dutch defense by transposition.
Tomashevsky pounced on his chances in the middle game and won a pawn. It was a rook and opposite colour Bishops endgame thereafter wherein the Russian came up with some emphatic technical display to go one up in the match.
The World chess cup started with 128 players as a knockout event with USD 1.6 million as prize money. It is also a part of the next world chess championship cycle for which the two finalists will qualify.
Initially there are two games mini-match under normal time control. In case of tied result, games of shorter duration are played to determine the winner.