CLIFTON, N.J. (AP) — Annika Sorenstam is walking away from LPGA Tour after this year and the Hall of Famer seems intent on leaving as the No. 1 player in women's golf.

Seeking her third straight win, Sorenstam kicked off her goodbye tour by shooting a 5-under 67 on Thursday for a share of the first-round lead in the Sybase Classic with Song-Hee Kim of South Korea and Rachel Hetherington of Australia.

Lurking a shot back is two-time defending champion Lorena Ochoa, the 26-year-old Mexican superstar who replaced Sorenstam as No. 1 last year.

``Lorena is playing some great golf last year, this year, so it's going to be tough to overtake,'' Sorenstam said of the fight for No. 1. ``But I'm going to do the best I can to have a great season, and I want to finish strong and play some good golf.''

Sorenstam probably would need to win two of the three remaining majors this year and have Ochoa finish out of the top 10, which has happened only once in eight events this year.

``It took me many years to get there, and now that I'm at the top, first I will try to enjoy it as much as I can, but I like to be there,'' Ochoa said. ``I like to win and I like the competition. I want to make sure I keep working hard to stay there.''

The goal this week for both will be winning at the traditional Upper Montclair Country Club in the shadow of New York City.

The $2 million event took on added significance on Tuesday when Sorenstam stunned the golf world by announcing that this would be her final season on tour. The disclosure came just two days after the 37-year-old posted a seven-stroke victory in the event at Kingsmill, the 72nd win of her career.

It also was her third win this year and her second straight, coming on the heels of her victory at the Stanford International Pro-Am on April 27 in a playoff with Paula Creamer. She took a week off between tournaments.

The retirement decision seemed to take a weight off her shoulders, and she now seems intent on having fun - and winning.

Sorenstam threw out the first ball at a New York Mets' game on Tuesday night and read the Top 10 list on David Letterman's show.

She got back to playing golf Thursday and had more fun playing in the group behind Ochoa. The Swede, who was bothered by back problems in a winless 2007, had five birdies in a bogey-free round.

``I'm just very happy the way I'm playing,'' Sorenstam said. ``I worked really hard this winter and it's all coming together. My swing fells really good and my putting feels really good. This is the way I enjoy the game. It's fairways and greens.''

Ochoa, who always keeps an eye on the scoreboard, noticed.

``Seeing Annika's name, we're all used to that,'' said Ochoa, a five-time winner this year and the tour's leading money winner. ``She's there every week.''

Ochoa had as many birdies as Sorenstam, but her round was marred by tough luck on the par-4 12th hole. The pin on the dogleg hole was back right and guarded by a pond. Ochoa's second shot from the fairway 196 yards away landed on the right edge and bounced into the pond. A foot the other way and she would have been putting for a birdie instead of bogey.

``You have to accept it's just a bad break,'' Ochoa said. ``I mean it's only the first day, so hopefully I'll get good breaks.''

Kim, who had a career-best second-place finish at the Corona Championship in Mexico in April, also had five birdies and no bogeys.

Hetherington, who like Kim played in the afternoon, had a bogey and six birdies, highlighted by three straight to finish the front nine.

Hetherington has eight career wins, including a 3-1 record against Sorenstam in playoffs. She beat her in the 1998 First Union Betsy King Classic, the 2002 PING Banner Health and 2003 Giant Eagle LPGA Classic. She lost to her in the 2000 Jamie Farr Kroger Classic.

The leaderboard was crowded after the first day of the 72-hole event.

Pat Hurst, Catriona Matthew, Brittany Lang, Teresa Lu and Carolina Llano joined Ochoa at 68.

U.S. Women's Open champion Cristie Kerr was in another big group at 69.