Simona Halep saved a match point before defeating Canadian teen Bianca Andreescu 3-6, 7-6, 6-3 at the WTA Finals in Shenzhen.
Both players sought medical treatment during the match, with Halep getting her foot treated while Andreescu had a lower back problem.
Elsewhere, defending champion Elina Svitolina stretched her unbeaten run at the season-ending tournament with a 7-6, 6-4 win over Karolina Pliskova.
Halep and Svitolina are now 1-0 in the Purple Group, while Andreescu and Pliskova are 0-1.

Dubai Basketball continues strong form across Europe
Fabrizio Romano reflects on independent media’s impact at BRIDGE
Desert Vipers down Gulf Giants to secure win in Super Over thriller
Fernandes double helps Man United to win as Wolves' misery continues
Real Madrid handed shock home loss as Celta Vigo spring surprise
