RICHMOND, Texas — Michelle Wie is gone, putting all the attention on Lorena Ochoa's player of the year battle with Jiyai Shin at the LPGA Tour Championship.

Wie withdrew from the season-ending event yesterday because of a sprained left ankle, hours after Ochoa shot a 6-under 66 to take a one-shot lead over Reilley Rankin.

The 20-year-old Wie, fresh off her first LPGA Tour victory last week at Ochoa's tournament in Mexico, shot a 72 in a windswept afternoon round. The Stanford student from Hawai'i limped through her round on the gimpy ankle that she sprained during the Solheim Cup in August, went for treatment afterward and withdrew about an hour later.

"I wanted to do everything I could do to fight through the injury," Wie said in a statement. "It bothered me last week in Mexico, but I was able to play through the pain. I realized today that I wouldn't be able to continue to play through it."

Wie was 3 under through 12 holes. Her ankle gave way on the 13th tee, and she stumbled backward, sliced her shot into the rough and took her first bogey. She bent over in apparent pain on No. 14, then slipped again hitting her tee shot on No. 17.

"I want to make sure that I'm being smart with it," she said. "I will return home to have it looked at by my doctors and follow their advice for treatment."

Ochoa teed off in the morning, before the wind picked up at the Houstonian Golf and Country Club.

She was four shots ahead of Shin (70) on the leaderboard, but the 21-year-old South Korean leads Ochoa 156-148 in the race to become the tour's player of the year. To earn the distinction this year, Ochoa must win this week or finish no worse than third and hope Shin places out of the top 10.

But Ochoa says she's actually feeling more relaxed this week after dealing with the demands of hosting a tournament a week ago.

"Last week was a little bit tough in many different ways with all the things to do and all the pressure," she said. "Everything is a little bit easier, if you compare it to last week."

Shin and Ochoa also are in a virtual dead heat for the Vare Trophy, given to the player with the season's lowest scoring average.

The 30-year-old Rankin also teed off early and finished her 67 before the wind became a factor.

The first round was suspended because of darkness with four groups still on the course.