Updated

Southport, England (SportsNetwork.com) - Mo Martin shot 3-under 69 for the second straight day Friday and she moved to the top of the leaderboard at the Women's British Open.

Martin, who is search of her first LPGA Tour title, completed 36 holes at 6- under-par 138. In 16 starts this season, she has a single top-20 finish, which came at the ShopRite LPGA Classic, where she closed with a 66.

So Yeon Ryu, the 2011 U.S. Women's Open champion, carded a 70 in round two. She was joined in second place at minus-3 by Beatriz Recari, who fired a 5- under 67 on Friday at Royal Birkdale Golf Club.

Sun Ju Ahn also posted a 67 to move into a share of fourth at minus-2. She stands alongside Julieta Granada, who posted a 70 on Friday.

Gwladys Nocera (70), Amy Yang (72), Ariya Jutanugarn (68) and Amelia Lewis (71) are the final players in red figures at 1-under-par 143.

Inbee Park, the 2012 runner-up, and Morgan Pressel headline a group of six players tied for 10th at even-par 144. Park shot 72 for the second straight round, while Pressel stumbled to a 74 in round two.

World No. 1 and defending champion Stacy Lewis (74), Suzann Pettersen (73) and Ai Miyazato (73) are among those at plus-1, while first-round leader Ayako Uehara struggled to a 7-over 79 and she tumbled into a share of 27th at 3-over 147.

Martin matched her round from Thursday with five birdies and two bogeys. She started round two with five straight pars. Martin followed with back-to-back birdies at six and seven to move to minus-5.

Around the turn, she picked up another birdie at the 10th, but trouble loomed. Martin stumbled to bogeys on the 11th and 12th to slide to minus-4.

Martin got one of those strokes back when she birdied the 15th. She closed with a birdie at the 18th to claim her 3-stroke lead.

"Well, it was quite fun. It's always nice when your plan pans out. So it's fun to be here. It's a fun day," Martin said. "I had a great pairing. It was a beautiful day. I didn't know the weather was this nice here, but it is, so it's been really fun."

This is Martin's third Women's British Open start. She missed the cut last year after finishing 57th in 2012. Her back-to-back 69s are her first two under-par rounds in this championship.

"My caddie and I figured out where the widest parts of the fairway were, where I would have the best approaches into the greens. I don't hit it particularly long, so I'm just capitalizing on my accuracy," said Martin of her plan to attack the course. "But just picking good targets, that's really key on this golf course, and executing it. And the rough, fortunately I haven't met it too much this week, just a few times."

Ryu stumbled out of the gate as she tripped to a double-bogey on the par-4 second. She got one shot back when she birdied the fourth. Ryu parred the final five holes of her opening nine.

The 24-year-old moved back to 2-under for the championship with birdies on the 10th and 11th. After six more pars, Ryu birdied the last to gain a share of second place.

Recari, who will defend her title next week at the Marathon Classic, started with six pars in a row. She moved to even-par for the championship with birdies on the seventh and ninth.

Around the turn, Recari faltered to a bogey on No. 10. She bounced back with a birdie on the par-3 12th. The Spaniard jumped into a share of second when she closed with three straight birdies from the 16th.

NOTES: Like Martin, Recari is having a tough season. In 12 starts, she has missed six cuts and hasn't finished inside the top 25 ... Lexi Thompson made the cut by one stroke despite taking a 10 on the first hole, where she hit her first two tee shots out of bounds ... The cut line fell at 6-over-par 150 with 70 players moving on to the weekend ... Among those missing the cut were three-time winner Karrie Webb, 2004 champ Karen Stupples, U.S. Women's Open champions Na Yeon Choi and Michelle Wie along with Caroline Hedwall, Yani Tseng and Catriona Matthew.