Fourth seed GM Nguyen Ngoc Truong Son of Vietnam outplayed erstwhile solo leader GM Meng Kong Wong of Singapore in the sixth round and then drew with GM Tigran Kotanjian of Armenia in the following round to assume the solo lead in the 4th PGMA Cup international chess championship Tuesday at the Duty Free Fiesta Mall in Parañaque City.

Nguyen, one of only two Vietnamese players in the 56-player field, hiked his score to 5.5 points on four wins and three draws in this nine-round tournament organized by the National Chess Federation of the Philippines (NCFP) in honor of President Arroyo.

Nguyen is now half a point ahead of top seed GM Michael Mchedlishvili of Georgia and six other players with only two rounds remaining.

Mchedlishvili, the highest-rated player here with an ELO of 2613, halved the point with GM Rogelio Antonio,Jr. in the sixth round and beat GM Pyotr Kostenko of Kazakhstan in the seventh round.

Second seed GM Gopal Nayanan of India, third seed GM Anton Filippov of Uzbekistan and sixth seed GM Merab Gagunashvili of Georgia also won.

Nayanan whipped GM-elect Ronald Dableo of the Philippines, Filippov dumped GM Dao Thien Hai of Vietnam and Gagunashvii crushed GM John Paul Gomez in the round six.

IM Richard Bitoon emerged as the highest-placed Filipino player with five points after drawing his matches against Kotanjian in the sixth round and fifth seed GM Ehsan Ghaemmaghami of Iran in the seventh.

The 33-year-old graduate of Southwestern University, who is seeded only 17th here with an ELO of 2490, has three wins and four draws.

Six other Filipino campaigners – Antonio, Gomez, Dableo, GM Darwin Laylo and Buenaventura Villamayor and IM Oliver Dimakiling – also stayed  within striking distance with 4.5 points.

After drawing with Mchedlishvili in the sixth round late Monday night, Antonio settled for a draw with Laylo.