Wuhan Open winner Sabalenka, currently 10th in the Race to Singapore leaderboard, must win in Tianjin this week, and also needs help from other results from Pliskova and Bertens to keep her qualifying bid alive.
Sabalenka recovered from an early break down in the opening set and saved three break points at 5-5 before winning the tiebreak.
A lapse in concentration cost Sabalenka the second set, but she roared back in style to drop only four points in the final five games of the match.
The 20-year-old is up against Poland's Magda Linette in the second round, who collected a win over Evgeniya Rodina in three sets on Monday.
Earlier in the day, Britain's Katie Boulter produced a sparkling display to upset eighth seed Maria Sakkari 7-6(4) 6-3.
(Reporting by Nivedita Balu in Bengaluru, editing by Pritha Sarkar)
