Chennai: Four-time national champion Surya Sekhar Ganguly of Petroleum sports board was upset by teammate G. N. Gopal in the 10th round of the Velammal National A chess championship here on Tuesday.

Though Ganguly suffered a setback, he continues to lead the table with 7.5 points, followed by teammates M. R. Venkatesh and Gopal with seven points each. Ganguly opted to play French defence, where he unnecessarily went for a pawn capture on the 14th move, which proved a costly mistake. He had to lose his bishop in the process and his opponent capitalised on it to post a win on the 40th move.

Both Barua, a former national champion from Tata Steel and M. S. Thejkumar of Karnataka lost on time after being in promising positions against PSPB players S. Arun Prasad and Venkatesh, respectively. Second seeded Grandmaster Abhijit Kunte of IndianOil improved his ranking when he defeated Neelotpal Das, a Grandmaster from PSPB in 33 moves. In a game between players from the same unit, K. Ratnakaran of Railways scored an impressive win over IM Suravjit Saha.        (PTI)