The Vietnamese defeated Vassily Ivanchuk of Ukraine in a 45-move match to earn 4.5 points.
He will next play Lu Shanglei who lost to Wang Hao in an all-Chinese game yesterday.
Wei Yi of the hosts maintained his position as the tournament leader with 5.5 points. He tied with Arkadij Naiditsch from Azerbaizan in the 46-move match.
The third place went to Ding Liren of China, who has four points.
The eighth edition of the tournament will continue until tomorrow on the island province of Hainan. This year the 10-player single round-robin format features five international grandmasters, as well as top Chinese players.