Double Grandmaster norm holder Tejas Bakre upset Grandmaster Surya Shekhar Ganguly of PSPB in the 20^th round at the National 'A' chess championship in Kozikhode on Wednesday to remain in contention for a place in the Indian side for the Olympiad.

Despite today's shock defeat, Ganguly maintains the lead at the top on 15 points. However, the margin is now reduced to just half a point after top seeded Grandmaster Pendyala Harikrishna of Andhra Pradesh and Grandmaster Sandipan Chanda of PSPB made most of Ganguly's fall, crushing their respective opponents.

With just three more rounds to go, British champion Grandmaster Abhijit Kunte of PSPB and Asian women champion Grandmaster Koneru Humpy of AP are tied in fourth spot on 13.5 points apiece while Barua continues to remain in sole sixth spot on 12.5.

Also in the race for a berth in the Indian team are Grandmaster R B Ramesh of PSPB and Bakre on 12 points.

Ganguly had to pay the price for being over-ambitious today as he could have had an easy draw. Bakre blitzed out the opening moves as the players followed routine theory of the Sicilian Richter Rauzer attack where Ganguly played white. Bakre felt the heat for some time in the middle game but was quick to recover with a couple of exchanges that led the game to a level queen and rook endgame.

Trying hard for the improbable victory, Ganguly did manage to slightly weaken Bakre's pawn structure but it was not enough.

As the game entered a queen ending, Ganguly blundered with a badly timed exchange of queens and much to his dismay realised a few moves later that the resulting position was lost.

Bakre made no mistakes from there and after 59 moves he handed Ganguly his first defeat of the championship.

On another board, Harikrishna cruised to another fine victory, accounting for IM Prathamesh Mokal from the white side of a Queen's Indian.

Hari ensured a slight advantage after taking the Bishop pair and surprised Mokal with a pawn sacrifice, which proved fatal. Mokal lost the queen for just a rook and the rest was simple manoeuvres for his opponent.

Chanda overpowered Suvrajit Saha of West Bengal in a Sicilian Nazdorf game where the former played white. Sensing some weaknesses in Suvrajit's position in the middle game, Chanda marshalled his forces well to let the game drift to a heavy pieces endgame where Suvrajit stood no chance.

Grabbing a few pawns, Chanda marched his queen pawn cautiously and romped home in 58 moves.

Humpy played a solid game to draw easily with her black pieces against Kunte while Barua had to work hard to beat veteran V Hariharan who played black.

Results (Round 20):

P Harikrishna (14.5) beat Prathamesh Mokal (9.5); Roktim Bandhopadhyay (9.5) beat Sriram Jha (7.5); Abhijit Kunte (13.5) drew Koneru Humpy (13.5); Dibyendu Barua (12.5) V Hariharan (4); Sandipan Chanda (14.5) beat Suvrajit Saha (8); S Vikramjit Singh (8) lost to Arghyadip Das (7.5); S Kidambi (11) beat Pravin Thipsay (10); S S Ganguly (15) lost to Tejas Bakre (12); R B Ramesh (12) beat Neelotpal Das (11); Vishal Sareen (7.5) drew Saptarshi Roy Chowdhury (10.5); M R

Venkatesh (10.5) beat S Satyapragyan (8); M Srinivasa Rao (2.5) drew T S Ravi (7.5).