Wuhan - Roberta Vinci downed Olympic gold medallist Monica Puig in the first round of the Wuhan Open on Sunday.
Vinci, last year's US Open finalist who halted Serena Williams' bid for a rare calendar-year Grand Slam, served eight aces en route to the second round of the $2.6m hard-court event.
Puig had a fairytale run at the Rio Olympics, bringing her island its first-ever gold medal and taking her to a career-high ranking of 33.
She then fell in the first round of the US Open, but made it to the quarter-finals in Tokyo last week, eventually losing to world number four Agnieszka Radwanska.
"It was a tough first round. I didn't necessarily play my best tennis," Puig told reporters after the Wuhan match.
"It's kind of hard when you have to focus on other things, other tournaments, and everybody keeps bringing you back to Rio," the 22-year-old added.
American qualifier Louisa Chirico was handed a pass to the second round after US Open quarter finalist Timea Bacsinszky became ill and retired in the second set.
Teenager Belinda Bencic also pulled out in the second set with a lower back problem, allowing world number 10 Svetlana Kuznetsova of Russia through to face either Briton Heather Watson or Madison Brengle of the USA.
Results from the first day of the Wuhan Open on Sunday (x denotes seeding):
Yanina Wickmayer (BEL) bt Shelby Rogers (USA) 6-3, 7-6 (7/1)
Yaroslava Shvedova (KAZ) bt Saisai Zheng (CHN) 6-0, 6-3
Roberta Vinci (ITA x13) bt Monica Puig (PUR) 6-3, 6-3
Katerina Siniakova (CZE) bt Timea Babos (HUN) 6-3, 7-5
Lucie Safarova (CZE) bt Varvara Lepchenko (USA) 7-5, 6-3
Laura Siegemund (GER) bt Danka Kovinic (MNE) 6-7 (7/9), 7-5, 6-4
Irina Begu (ROM) bt Elizaveta Kulichkova (RUS) 4-6, 7-6 (7/4), 6-2
Louisa Chirico (USA) bt Timea Bacsinszky (SUI x12) 6-3, 4-3 (ret)
Svetlana Kuznetsova (RUS x9) bt Belinda Bencic (SUI) 6-3, 3-4 (ret)
Ekaterina Makarova (RUS) bt Sabine Lisicki (GER) 6-1, 6-2