Venus Williams won her opening match of the inaugural WTA Elite Trophy with a three-set win over fellow American Madison Keys in Zhuhai on Tuesday.
After losing the first set, Williams went on to beat Keys 3-6, 7-6 (5), 6-1 in two hours and nine minutes.
The opening three games of the first set were all breaks of serve with Keys leading 2-1, she broke serve again for the third time in the seventh game to lead 5-2.
Williams got one break back but then was broken again for Keys to win the set 6-3.
In the second set, the pair shared two breaks each before the match went to a tiebreaker.
Williams was leading 4-2 at the change of ends in the breaker and Keys then pulled back to 4-4, but Williams upped her intensity to win three of the next four points and clinch the second set and breaker 7-5.
The final set was dominated by Williams, who led 5-0 before going on to win the set and match 6-1. The result moved Williams to the top of Group A in the tournament.
Meanwhile, Jelena Jankovic also climbed to the summit of her group after she pulled off an against-the-odds win over world number 18 Sara Errani.
Jankovic wasted little time in the first set, winning four consecutive games to open a 5-2 lead. The Serbian looked likely to wrap up the set in the next game, but Errani defended four breakpoints to hold her serve before breaking back to keep her hopes alive.
Unfortunately, the Italian’s efforts were rendered meaningless when she dropped her serve again in the tenth game to lose 6-4.
The second set was a back and forth battle, with both players fighting tooth and nail for victory. With the scores at 4-4 after two breaks each, the ninth game would prove the turning point.
Jankovic defended four break points to hold her serve, then came within a point of breaking Errani and winning the match in the tenth game, before holding again and breaking the Italian in the final game for a 7-5 win.
Jankovic now tops Group C, with Erani in third and Karolina Pliskova, who is yet to play, in second place.
Elina Svitolina also battled her way to a straight sets win against Andrea Petkovic in the final match of the day.
Svitolina needed just over two hours to secure a 7-6(7-4), 6-3 victory, and climb to the top of the standings in Group B.
The pair were evenly matched right up until the final third of the second set, when Svitolina raced to three consecutive against a diminished Petkovic to seal the win.