Michelle Wie will defend her title, while LPGA Tour leader Yani Tseng is the favorite at the Canadian Women's Open.

The 22-year-old from Taiwan has dominated with four victories this season, including wins in three of the last six events.

"World No. 1 has been my goal since I was 12," Tseng said Wednesday. "To become No. 1 is very exciting."

Tseng tops the LPGA money list with $1.7 million and ranks first in scoring average (69.63), average driving distance (269.3 yards) and top-10 finishes (9 in 14 tournaments).

The Canadian Open, which gets underway Thursday at Hillsdale Golf Club, is a tournament she's never won.

Tseng tied for sixth in Edmonton in 2007 in her LPGA debut and placed third in 2008 after a case of nerves cost her the lead with a final-round 77 in Ottawa. She was 33rd the following year in Calgary and missed the cut last year in Winnipeg.

"I was so nervous because I didn't know anything about the LPGA or anything about the field and playing the best players in the world," she said of her debut. "But I learned a lot. I made double on the last hole. I lost a lot of money. That's the first time I go 'Wow, one shot makes a lot of difference on the LPGA Tour.'"

She finished 13th last week at the Safeway Classic in Oregon, and chalked it up to jet lag after returning from Taiwan.

For the 21-year-old Wie, the Canadian Open was only her second win in three years on the tour. Tseng has already won five majors, including this year's LPGA Championship and Women's British Open, which she won for a second straight time.

"It is very motivating to see someone like Yani get really good over the last year and half," said Wie, who will focus full-time on golf after she graduates in March from Stanford with a communications degree. "It's kind of something I want to see about myself. I want someone to say next year how good I've become."

The tournament will field 19 of the world's top 20 players for an event that lost its major status in 2000 but still has major prize money at $2.25 million.

The contenders include Cristie Kerr, the 2006 winner, who is second on the money list, and Suzann Pettersen, the 2009 champion. Pettersen rallied from a nine-stroke deficit on Sunday to win the Safeway Classic.

Australia's Katherine Hull is 47th on the money list with one top-10 finish this year, but she's had solid results in Canada. She won the tournament in 2008 and was second in 2005. She lost the 2010 British Open by one stroke to Tseng.

Lorie Kane of Canada closed with a 68-67 last year to finish tied for 11th. She's the last Canadian to win an LPGA tournament, back in 2001.

"I'd be lying if I told you that I wasn't thinking that I would very much like to win, because that's why I'm here," said the 46-year-old Kane. "To hoist the CN Canadian Women's trophy would be fantastic."