Britain's Heather Watson went through to the second round of the Tianjin Open in China with a 6-4 7-6 win over Kateryna Bondarenko of Ukraine.
The British number two will play either second seed Wang Qiang or qualifier Arina Rodionova next.
Swede Rebecca Peterson earned a shock 6-3 4-6 6-3 victory over seven-time Grand Slam champion Venus Williams, 39.
The 24-year-old said: "It was such a privilege to play such a champion. I was just trying to enjoy it."
On Tuesday, Britain's Harriet Dart plays Japan's Kurumi Nara.