Country's youngest-ever GM-norm holder Parimarjan Negi played an excellent game to upset Grandmaster Ziaur Rahman of Bangladesh in the fourth round of Parsvnath International Open chess tournament in Delhi on Tuesday.

The 12-year-old, hunting for his second GM-norm here, is sitting pretty with full score of four points to share the lead with five others in the Rs 7.5 lakh tournament.

Top seed GM Alexei Fedorov of Belarus, GM Marat Dzhumaev of Uzbekistan and FIDE Master Zhumabaev, besides India's GM R B Ramesh and IM Arun Prasad are among those on the top of the table.

In other matches, Ramesh played a long-drawn game to clinch a win against IM Saptarshi Roy Chowdhury; GM Abhijit Kunte drew with woman Grandmaster Tania Sachdev while GM Pavel Kotsur of Kazakhstan and IM Roktim Bandhopadhyay also split points.

Negi played an attacking game with white in the Modern Defence opening and got a favourable position by sacrificing a knight to rip open black's castled position.

He again sacrificed a rook for knight and by the time Rahman fought back, Negi had an extra pawn to boast of in the endgame.

It was not easy to extract a win after a complicated middle game but with his technique and maturity that belies his age, the Delhi boy won in 64 moves.

"I missed some of his moves in the middle game and the position was quite complicated before I made the sacrifice," said Negi after the game.

On the top board, Fedorov defeated Vikramaditya Kamble in a French Defence game.

Going for the topical Winawer Variation, Fedorov delivered the winner's punch in the middle game itself, leaving Kamble defenseless against white pieces.

Dzhumaev was also in top form against National junior champion and Grandmaster-norm holder Deep Sengupta in another French Defense game of the day.

Sengupta, black, allowed Dzhumaev to get a promising position after the opening and an erroneous plan by him soon after led to the demise of his queen. The rest was child's play for the Uzbek Grandmaster who notched the full point after just 38 moves.

• Complete chess coverage