Levon Aronian of Armenia suffered a shocking ouster from the World Chess Cup, losing to Russian Dmitry Jakovenko in the tie-breaker of the fourth round, in Khanty Mansiysk, Russia.
Gata Kamsky of the United States caused a flutter, defeating Russian Peter Svidler in the other tie-breaker while Evgeny Alekseev was the other Russian to win impressively against compatriot Evgeny Bareev.
Earlier, Sergey Karjakin of Ukraine, Alexei Shirov of Spain, Magnus Carlsen of Norway, Ruslan Ponomariov of Ukraine and Ivan Cheparinov of Bulgaria won in normal games to book places in the quarter-finals.
The line-up in the last eight has fast-improving Alekseev facing Karjakin while Jakovenko has a tough task against Alexei Shirov.
Kamsky takes on Ponomariov and Carlsen meets Cheparinov.
The World Cup, that started with 128 players, has a winner's purse of US $120,000. The last Indian to get eliminated was Krishnan Sasikiran, who lost to Ponomariov in the first game of the two-game mini-match and drew the second.
Jakovenko came up with an opening novelty against Aronian in the first rapid game and kept things under control for major part after accepting a pawn sacrifice early in the Ruy Lopez opening.
Aronian felt the heat in the middle game when he was troubled by dominating white knights in the centre and eventually lost after 66 moves.
In the return game Aronian fought in vain for 114 moves but Jakovenko never slipped and finally got the draw he was looking for.
Kamsky outplayed Svidler from a level position arising out of another Ruy Lopez in the second game after the first was drawn.
According to experts, Svidler tried hard after Kamsky equalised and had to pay a heavy price.
In the other match of the day, Alekseev won both games in rapid against Bareev and sailed through to the quarters.
Complete results round 4:
Sergey Karjakin (Ukr) beat Liviu-Dieter Nisipeanu (Rou) 1.5-0.5; Evgeny Alekseev (Rus) beat Evgeny Bareev (Rus) 3-1; Levon Aronian (Arm) lost to Dmitry Jakovenko (Rus) 1.5-2.5; Vladimir Akopian (Arm) lost to Alexei Shirov (Esp) 0.5-1.5; Ruslan Ponomariov (Ukr) beat Krishnan Sasikiran (Ind) 1.5-0.5; Gata Kamsky (Usa) beat Peter Svidler (Rus) 2.5-1.5; Magnus Carlsen (Nor) beat Michael Adams (Eng) 1.5-0.5; Ivan Cheparinov (Bul) beat Wang Yue (Chn) 1.5-0.5.