CINCINNATI (AP) — Serena Williams arrived at the Western & Southern Open with an Olympic gold medal and a chance to win another tournament she had never won before.

Really, Serena, you haven't won here before.

During a pre-tournament news conference Monday, Williams was confused about whether she had taken a title in Cincinnati.

"I did win this tournament, didn't I?" she said. "Maybe I didn't. I can't keep up. I don't think I did. OK. Whoops."

She has played the Cincinnati tournament three times, her best showing a semifinal loss in 2006.

Williams is scheduled to open play Tuesday night. The women's tournament began Monday and was capped later in the night by Shuai Peng's 5-7, 7-5, 7-6 (8) upset of 13th-seeded Jelena Jankovic of Serbia in a match delayed 40 minutes by rain.

Jankovic, last year's runner-up and the 2009 champion, lost at love while serving for the match in the second set, including a double-fault at love-40, and blew a total of five match points against her Chinese opponent.

Williams followed-up her Wimbledon championship in July by overwhelming Maria Sharapova 6-0, 6-1 to win the Olympics singles title.

The 31-year-old, ranked No. 4 in the world and seeded second at the $5.7 million event, spent a week training in Paris before arriving in Cincinnati. She still was basking in the glow of winning both the singles and, with older sister Venus, the Olympic doubles championship.

"It was really awesome to win both medals at the Olympics," she said.

And those gold medals are safely tucked away.

"My gold medals are in a location I probably shouldn't say, in case someone wants to go and take them," she said. "They're not with me."

Williams now can turn her attention to closing out her hard court season, which ends with the U.S. Open starting Aug. 27 in New York. She said he recent success on grass does not have her wishing to play on it more.

"I actually never really liked grass. It's never been my favorite surface. Now, I like it, but I love hardcourts," she said.

Thirteenth-seeded Alexandr Dolgopolov became the first player upset at Cincinnati, falling to 50th-ranked Nikolay Davydenko 6-1, 6-1 in the first round Monday.

Davydenko, ranked as high as No. 3 on the tour in 2006 and 2007, needed just 52 minutes to oust Dolgopolov, who was coming off winning the Citi Open in Washington on Aug. 5. Continued...