Choi in front at Samsung World Championship

Oct 4, 2008 - 11:14 AM HALF MOON BAY, California (Ticker) -- Na Yeon Choi owns a two-stroke lead entering Saturday's third round of the Samsung World Championship.

It was a windy and tough second round at Half Moon Bay Golf Links' Ocean Course and the scores reflected it. Choi carded a 1-under-par 71 on Friday and was able to move up the leaderboard, while first-round leader Ji-Yai Shin slipped three strokes back after a 76.

At 4-under 140, Choi has a two-stroke lead over four players, including world No. 1 Lorena Ochoa and Paula Creamer.

Conditions were more favorable at the start of the day and Choi began her round with a birdie at No. 1 and added another at No. 8. She had only one more the rest of the day, at the 18th, after consecutive bogeys at Nos. 13 and 14.

For a while it looked like Ochoa was going to run away and hide from the field as she reeled off five straight birdies starting on No. 4. Then the winds picked up and she cooled off.

The two-time reigning champion's birdie streak ended with a double-bogey at the par-3 ninth and Ochoa suffered another double at the par-4 13th. She dropped shots at Nos. 16 and 18 as well and is tied for second at 2-under 142 after a 73.

Song-Hee Kim (73), Angela Stanford (73) and Creamer (74) are tied for second with Ochoa.

Katherine Hull (73), Yani Tseng (74) and Shin are at 1-under. Shin shot an opening-round 67, but had seven bogeys on Friday and did not make her first birdie until No. 14.

Ochoa is looking to become the fourth player to win this event at least three times, including five-time winner Annika Sorenstam.

The Swedish star, who was paired with Ochoa, struggled to a 5-over 77 and is six shots off the pace at 2-over 146 through 36 holes.

First prize is $250,000.