Kolkata, Sep 9 - Grandmaster Le Quang Liem of Vietnam won his top board encounter against Uzbek GM Anton Filippov to sit pretty on top of the heap after the penultimate round at the 4th Kolkata Open Grandmaster Chess Tournament here Wednesday.

Le (7.5) employed his favourite Caro-Kann defence and soon there were opposite coloured bishops and a few other pieces on the board. The Vietnamese used his better developed pieces to get in a kingside attack and Filippov (6.5) had to eventually throw in the towel in a hopeless position.

GM Viktor Laznicka (7), half a point adrift of Liem, has emerged as the closest challenger of the leader.

Both Liem and Laznicka have already met each other and will be playing different opponents in the final round.

Laznicka won a fine game against Evgeny Postny (6) of Israel to get the sole second spot. He defended the desperate kingside attack of the Israeli to eventually win a pawn in the endgame after which it was easy for him.

British GM Nigel Short (6)could not break through the defences of IM S. Satyapragyan (6) and settled for a draw, even though he had the better pawn structure.

IM R.R. Laxman (6) became the country's nineteenth Grandmaster after he got a draw against GM Rauf Mamedov of Azerbaijan. He has completed all his three norms and also the rating threshold of 2500 stipulated by world body FIDE.

FM Sahaj Grover topped off a wonderful tournament with his maiden GM norm. He drew against IM Sriram Jha. Sahaj already has the requisite number of IM norms but has not yet touched the 2400 rating threshold.

Both Sandipan Chanda (6.5) and Surya Sekhar Ganguly (6.5) won their respective games against IM B.Adhiban (5.5) and GM Rustam Khusnutdinov (5.