Grandmaster Krishnan Sasikiran mishandled a winning position and went down to Kazakh Grandmaster Darmen Sadvakasov in the fifth round, as other Indians also conceded points, in Group 'A1' at the Aeroflot International Open Chess tournament in Moscow.
National champion Surya Shekhar Ganguly lost to Wang Hao of China in what was an extremely good opening preparation by the Chinese, while former World junior champion P Harikrishna also miscalculated in a winning position and was held to a draw by Li Chao of China.
On other boards, S Vijayalakshmi and Parimarjan Negi suffered contrasting defeats against Ildar Khairullin of Russia and Alexander Ivanov of the United States respectively.
Women Grandmaster D Harika was the saving grace as she held GM Evgeny Najer to a creditable draw.
With only three more rounds remaining in the US $100,000 prize-money tournament, Sasikiran, Ganguly and Harika lead the Indian challenge with 2.5 points apiece; they all needed a too-good finish to be amongst the top winners.
Stanislav Novikov of Russia, who had 4.5 points, leads the event.
In Group 'C', Indians had more to cheer about as R Arun Karthik remained in joint lead on six points after settling for a draw with Vasif Durarbeyli of Azerbaijan in the seventh round game.
Karthik, who is gunning for the US $5000 top prize in this section, took his tally to a commendable six points out of a possible seven.
International Master Suvrajit Saha also remained in contention for top honours after taking a draw with David Kalashian of Armenia and inching himself up to 5.5 points.
Sasikiran was plain unlucky not to win an extremely commanding position against Sadvakasov, who played the black side of a Nimzo Indian defense and was slowly out-manoeuvred in the middle game.
Sasikiran was offered a rook for a Bishop in the early stages of the middle game itself as the Kazakh found himself nearly crippled but the Indian judiciously declined the offer and instead went for further tightening the noose.
However, the clock ticked away and Sasikiran found himself running short of time even as the position remained overwhelming. It was here that the Indian did not keep the momentum and a series of erroneous moves led to disaster.
Ganguly was overshadowed in the French defense game where Wang Hao played white and displayed his deep preparation. At one point in the game Ganguly had about 40 minutes left while
Hao had used just used two minutes of his allotted time.
Making matters worse was an inferior endgame for Ganguly and he stood no chance against marauding white rooks.
Harikrishna missed once again. It was a momentary lapse in concentration that made the difference between a full and a half point for the Indian against Li Chao.
Having a clearly won position with an extra pawn to back him in the endgame, Harikrishna missed a simple trick and allowed Chao to liquidate to a drawn position.
Results round 5: (Indians unless specified)
'A1: Krishnan Sasikiran (2.5) lost to Darmen Sadvakasov (Kaz, 3.5); Wang Hao (Chn, 3.5) beat Surya Shekhar Ganguly (2.5); Evgeny Najer (Rus, 2.5) drew with D Harika (2.5); Li Chao (Chn, 2) drew with P Harikrishna (2); Ildar Khairullin (Rus, 2.5) beat S Vijayalakshmi (1.5); Alexander Ivanov (2) beat Parimarjan Negi (1).
A2: Abhijit Kunte (3.5) drew with Anna Ushenina (Ukr, 3.5); Deepan Chakkravarthy (3) drew with Oleg Aleshin (Rus, 3); G Rohit (3.5) beat Nikolai Kabanov (Rus, 2.5); Arsen Yegiazarian (Arm, 3) drew with S Meenakshi (3); G N Gopal (2.5) drew with Igor Yagupov (Rus, 2.5); Deep Sengupta (1.5) lost to Sergej Mihajlovski (Blr, 2.5); Jakov Gellar (Rus, 2) beat S Arun Prasad (1); Vasily Papin (Rus, 2) beat Tania Sachdev (1) ; Lanka Ravi (1) drew with Maria Fominykh (Rus, 1); Ashwin Jayaram (1) drew with Kiril Kuderinov (Rus, 0.5).
'B' round 7: R Arun Karthik (6) drew with Vasif Durarbeyli (Aze, 6); David Kalashian (Arm, 5.5) drew with Suvrajit Saha (5.5); Dinesh Kumar Sharma (5) beat Daria Charochkina (Rus, 4); Aarthie Ramaswamy (4.5) drew with Sergey Shurygin (Rus, 4.5); Sahaj Grover (3.5) lost to Maria Kursova (4.5); Baira Kovanova (Rus, 4) beat Padmini Rout (3); Abhishek Das (4) beat Anastasia Savina (Rus, 3); B Adhiban (3.5) beat Alexandre Vuilleumier (Sui, 2.5).
'C' round 7: Sergei Volkov (Rus, 5.5) beat P Priya (4.5); Amrutha Mokal (4.5) drew with Igor Golberg (Isr, 4.5); Alexander Elkin (Rus, 4) lost to Soumya Swaminathan (5); Vladimir Moquila (Kaz, 4) beat P Sivasankari (3); Mahima Rajmohan (3) lost to Lettore Rudbig (Ita, 4).