Sriram Jha in action at Gorky Sadan on Monday. A Telegraph picture

Calcutta: The Armenian Grandmaster, Tigran Petrosian, jumped into sole lead with 7.5 points after the penultimate round of the Calcutta Open Grandmasters’ Chess Tournament at Gorky Sadan on Monday.

Overnight leader Darmen Sadvakasov, playing against Dimitri Komarov, blundered from a superior position which arose from a French Defence and lost.

Diwakar Prasad Singh spurned the offer for a draw from Petrosian on the 23rd move as he required two wins in the last two rounds for a GM norm.

Diwakar, playing black, even obtained a slightly better position in a Ruy Lopez exchange variation, but went astray due to time pressure in the endgame. He allowed an unstoppable passed pawn to his opponent and lost.

After the game, Perosian said, “I was a little apprehensive playing against Singh after what I had read in the newspapers. I opted for the exchange variation in the Ruy Lopez, exchanging queens, because it is easier to play against a computer with the queens off the board… I was surprised by the strength of his moves Nh6 and C6 which he made in two minutes… A GM should give it about 20 minutes of thought. If he plays like this, he can be a world champion…”

G.N. Gopal and Sriram Jha made their maiden GM norms and expectedly drew their game in a few minutes.

The 17-year-old Gopal, who will be appearing for his Higher Secondary Examinations later this month, said, “I should have got the norm Sunday, but I was quite tense and faltered in a simple rook ending. I plan to get two more norms within a year”

Six players — Arghyadip Das, Aditya Udeshi, Lalith Babu, K. Ratnakaran, S.P. Sethuraman and Vikramaditya Kamble confirmed their IM norms.

ROUND IX RESULTS

Darmen Sadvakasov(7) lost to Dimitri Komarov(6.5); Tigran Petrosian(7.5) bt D.P. Singh(5.5); R.B. Ramesh (5.5) lost to Serjei Tiviakov (6.5); Alon Greenfeld (6) drew Saidali Iuldachev (6); Safin Sukhrat (6) drew Mikheil Kekelidze (6); Sriram Jha (6) drew G.N. Gopal (6); Aditya Udeshi (5) lost to Surya Sekhar Ganguly(6); P.D.S. Girinath(5.5) drew Ziaur Rahman(5.5); Abhijit Kunte (6) bt M.R. Lalith Babu (5); Deepan Chakravarthy (5.5) drew Arun Prasad (5.5); Vijayalakshmi Subbaraman (6) bt Dibyendu Barua (5); B.T. Murali Krishnan (5) lost to Sundarajan Kidambi (6); Vikramaditya Kamble (5.5) drew Sergey Kasparov (5); Alexander Fominyh (5) drew Tejas Bakre (5); Abdulla Al-Rakib (5) drew with Roktim Bandyopadhyay (5).