Liem, seeded No 31 in the world, met almost no difficulty against the unknown rival, who is outside the world's top 100 rankings.
His next opponent will be Lu Yijie of China, who beat Vietnamese FIDE master Dang Hoang Son the same day.
In another match, Vietnam's GM, Nguyen Ngoc Truong Son, was defeated by the untitled Yeoh Li Tian of Malaysia .
Meanwhile, rising national star and world under-10 champion Nguyen Anh Khoi also made a bad start with a loss to Yeoh Li Tian of China.
The HDBank Cup is now in its third year, offering a bountiful reward pot with the champion receiving $10,000. The final round is scheduled to be played on March 25.
Last year Chinese master Ni Hua took the title.
What the stars mean:
★ Poor ★ ★ Promising ★★★ Good ★★★★ Very good ★★★★★ Exceptional