In the Master Open, Tabatabaei led alone with seven points. He won his game against GM Jeffery Xiong (USA, starting number 1), who had 90 more Elo points, as the only player of the top section, hunonchess.com reported, according to IRNA.
GM Tabatabaei received his grandmaster title in 2018 and is currently the world number 3 of the U-18.
Alexander Donchenko from Germany and American Gata Kamsky finished in second and third place both with 6.5 points.
Santosh Gujrathi Vidit from India won the Grand Master Tournament.
The Biel International Chess Festival is an annual chess tournament that takes place in Biel/Bienne, Switzerland.
It consists of two events, the Grandmaster Tournament, held with the round-robin system, and the Master Open Tournament (MTO), held with the Swiss system.
The Grandmaster Tournament has taken place since 1977. The city of Biel hosted three Interzonal Tournaments, in 1976, 1985 and 1993.