QUEBEC CITY — Nadia Petrova defeated Bethanie Mattek in three sets to win the WTA's Bell Challenge title today.

The top-seeded Russian lost the opening set 6-4 before coming back 6-4, 6-1 against the sixth-seeded American.

"I won this mental battle," Petrova said.

The 140 points Petrova earned with this title will allow her to participate as an alternate in the year-end Sony Ericsson WTA Championship in Doha, Qatar.

In the doubles final, Germany's Anna-Lena Groenefeld and American Vania King topped Jill Craybas of the U.S. and Tamarine Tanasugarn of Thailand 7-6 (3), 6-4.

It was the second doubles title this year for both players.