Venus won Olympic gold in the doubles with sister Venus in Beijing last year
Venus Williams made a winning return to the scene of her Olympic doubles triumph with an opening victory over Vera Dushevina at the China Open.
The American came back from 4-0 down in the second set to win 6-2 7-6 (7-1) at the Olympic Green Tennis Centre.
Tenth seed Flavia Pennetta of Italy beat China's Han Xinyun 7-6 (7-2) 6-2.
Dinara Safina and Serena Williams are among the leading women in action in Beijing, while Rafael Nadal and Novak Djokovic head a strong men's field.
Venus Williams struggled to close out her first-round match, reeling off five games in a row before failing to serve out at 5-4 and requiring a tie-break.
"It got away from me," said the 29-year-old, who lost in the first round in Tokyo last week.
"I started making a few too many errors out there. I was still just focused on winning the set, and focusing on not giving too much more away.
"I was just confident that if I kept getting games, I'd make her uncomfortable and make her start thinking about it."
Other winners on day one were Alize Cornet, who defeated 15th seed Samantha Stosur 6-4 4-6 6-3, Anastasia Pavlyuchenkova and Aleksandra Wozniak.
Safina and Serena Williams will begin their campaigns on Sunday, against Roberta Vinci and Kaia Kanepi respectively, before the men's event starts on Monday.
Serbia's Ana Ivanovic, the 11th seed, withdrew from the tournament, citing illness.