Qualifier Monica Niculescu of Romania disappointed the crowd in Beijing with a 6-4, 6-0 thumping of the fourth-seeded Li. It was Li's first match in her native country since winning the title at Roland Garros in the spring.
Li has struggled since becoming the first Chinese Grand Slam champ, with a semifinal finish at the U.S. Open tuneup in New Haven her best result in seven tournaments after Paris. She went out in the second round at Wimbledon and was a first-round loser to Simona Halep in Flushing Meadows.
Stosur beat Li in the third round at the U.S. Open tuneups in Toronto and Cincinnati before going on to capture her first Grand Slam championship in New York. She dropped her first match after beating Serena Williams in the U.S. Open final with a second-round setback to Maria Kirilenko in Tokyo last week, but claimed a 6-4, 6-0 triumph over Tsvetana Pironkova on Sunday.
Another matchup with Kirilenko is possible in the second round this week, but the Russian will have to beat Germany's Julia Goerges in her first-round match on Monday.
The eighth-seeded Bartoli rallied past Iveta Benesova, 3-6, 6-4, 7-5, while the only other seeded winners Sunday were No. 13 Anastasia Pavlyuchenkova of Russia and 14th-seeded German Sabine Lisicki. Pavlyuchenkova notched a 7-5, 6-4 win over Czech qualifier Barbora Zahlavova Strycova, while Lisicki took the first set, 6-2, against Irina-Camelia Begu before the Romanian retired with a right shoulder injury.
Also Sunday, Kaia Kanepi of Estonia and Slovakia's Dominika Cibulkova each knocked out a Chinese wild card entry. Kanepi earned a 6-0, 6-3 win over Zheng Saisai and Cibulkova cruised to a 6-0, 6-2 victory over Zhang Shuai.
Former world No. 1 Ana Ivanovic blasted Japanese veteran Kimiko Date-Krumm, 6-1, 6-1; Slovakia's Daniela Hantuchova pasted Greek qualifier Eleni Daniilidou, 6-4, 6-2; Spain's Maria Jose Martinez Sanchez dumped Israel's Shahar Peer, 6-1, 7-5; and Slovenia's Polona Hercog nosed past British qualifier Laura Robson, 6-4, 6-3.
There are also four second-round matches on tap, highlighted by a matchup of former French Open winners in Ivanovic and Svetlana Kuznetsova. Another French champ, Francesca Schiavone, will meet Cibulkova in the second round, while Wimbledon champ Petra Kvitova will take on Sweden's Sofia Arvidsson.
The 2011 China Open champion will pocket $775,500.