Pornanong Phatlum, Ranked No. 97, Leads the Women’s British Open

Pornanong Phatlum of Thailand is standing out at the Women’s British Open for more than just her pink golf ball.

Pornanong, ranked 97th, has yet to drop a shot in two straight rounds of five-under-par 67 that will give her a one-stroke lead heading into the weekend at the Open, the year’s fourth major.

While Minjee Lee and Mamiko Higa, the first-round leader and runner-up, encountered problems down the stretch on Friday at a rainy Royal Lytham and gave up two-shot leads, Pornanong played a steady hand and put her pink ball in all the right places — specifically, outside the many bunkers that define the course.

Pornanong, a 28-year-old Thai, missed a 10-foot putt for birdie in front of the clubhouse on the 18th green, but that did not get her down. She was 10 under over all.

“I’ve had a game plan,” Pornanong said. “I try to plan every shot, every hole.”

That has given her a great chance of winning a first major title and of claiming a first victory on the L.P.G.A. Tour. Her last victory was on the Asian Tour in January 2015, and she has only one top-10 finish all year.

Pornanong’s only top-10 finish at a major was a tie for seventh at the United States Women’s Open in 2014.

She has already put some distance between herself and many of the big names in women’s golf.

Top-ranked Ariya Jutanugarn was seven shots back after rounds of 71 and 70. No. 6 Shanshan Feng (71-71) was one stroke further back, and No. 2 Inbee Park (76-74) missed the cut.

Only six players were within five shots of Pornanong. They all have pedigrees, though.

Lee was in a three-way tie for second place at nine under. She was clear at 12 under before she double-bogeyed No. 16 and dropped a shot at No. 17, posting a 70. Lee, an Australian with a career-high ranking of No. 8, was runner-up on the Gullane links in the Ladies Scottish Open last week.

The home favorite Georgia Hall (68) was also in the tie for second, along with Higa, who was leading by two strokes at 11 under when she lost her ball in a gorse bush at No. 17 and ended up with a double-bogey 6.

Third-ranked Park Sung-hyun, who won the Women’s PGA Championship last month, is lurking in sixth place at seven under after rounds of 67 and 70.