Top-ranked Aryna Sabalenka eased to a straight-set victory over Zheng Qinwen in the opening match of the WTA Finals in Saudi Arabia on Saturday. Sabalenka won 6-3, 6-4 to extend her perfect record against the Chinese player to 5-0. The seventh-seeded Zheng lost the last three games as her focus slipped, and also appeared to have lost track of the score.