Former world number one Venus Williams claimed the 700th win of her career, beating Germany's Julia Goerges 6-4 6-3 in the second round of the Wuhan Open in China.
The 35-year-old American became the ninth woman to chalk up 700 victories since tennis turned professional in 1968 but still has a long way to go to catch all-time leader Martina Navratilova (1,442).
"I'm glad nobody told me before, I would have been a little bit nervous," Williams said.
"It was a good match, she's a quality player."
Two other former world number ones did not fare so well.
Denmark's Caroline Wozniacki was beaten 1-6 6-4 7-6 (6) by Anna Karolina Schmiedlova after blowing a 6-1 4-1 lead in a marathon match that lasted almost three hours.
"I'm very, very happy and very, very tired right now," said Slovak Schmiedlova.
Belarussian Victoria Azarenka was another early casualty, retiring from her match with Britain's Johanna Konta because of a leg injury while trailing 6-4 1-0.
Top-seed Simona Halep, meanwhile, sealed a straightforward win to move into the third round.
The Romanian beat Russia's Anastasia Pavlyuchenkova 6-2 6-1.
1-Simona Halep (Romania) beat Anastasia Pavlyuchenkova (Russia) 6-2 6-1
3-Petra Kvitova (Czech Republic) beat Daria Gavrilova (Russia) 6-3 4-6 7-5
Venus Williams (U.S.) beat Julia Goerges (Germany) 6-4 6-3
5-Garbine Muguruza Blanco (Spain) beat Sloane Stephens (U.S.) 6-2 6-0
15-Roberta Vinci (Italy) beat Irina Begu (Romania) 6-4 6-3
Anna Karolina Schmiedlova (Slovakia) beat 4-Caroline Wozniacki (Denmark) 1-6 6-4 7-6(6)
Johanna Konta (Britain) beat Victoria Azarenka (Belarus) 6-4 1-0 (Azarenka retired)
CoCo Vandeweghe (U.S.) beat Caroline Garcia (France) 6-3 6-7(4) 7-6(6)
7-Carla Suarez Navarro (Spain) beat Monica Niculescu (Romania) 5-7 6-3 6-4
Camila Giorgi (Italy) beat 11-Belinda Bencic (Switzerland) 6-2 0-0 (Bencic retired)
6-Angelique Kerber (Germany) beat Jelena Jankovic (Serbia) 6-4 2-6 6-2
Kristina Mladenovic (France) beat 14-Madison Keys (U.S.) 7-5 1-6 6-2
12-Elina Svitolina (Ukraine) beat Varvara Lepchenko (U.S.) 6-4 6-2
9-Ana Ivanovic (Serbia) beat Madison Brengle (U.S.) 6-0 6-3