Zhuhai - Top-seeded Venus Williams rallied to beat Saisai Zheng of China, 4-6, 6-1, 6-1 to reach the semi-finals of the WTA Elite Trophy on Thursday.
Williams hit six aces and saved two of four break points to dispatch No 12 Zheng and improve to 2-0 in Group A.
The tournament brings together 11 of the top players who did not qualify for last week's WTA Finals in Singapore, including Caroline Wozniacki, Jelena Jankovic and Roberta Vinci.
Zheng was granted a wild-card berth.
The qualifiers compete in a four-group round robin format, with the winners of each group advancing to the semifinals.
One player from the field can move into the Top 10 on Monday and Williams is in a race for that spot with Carla Suárez Navarro, Karolina Pliskova and Vinci.