Bianca Pagdanganan opened her campaign at the US Women’s Open with a resilient one-under-par 70, overcoming an early setback to stay firmly in contention at Riviera Country Club in Pacific Palisades, California.

Bianca surged up the leaderboard with three consecutive birdies starting on the fifth hole, showcasing the form that has made her one of the Philippines’ top golfers. A costly double bogey on No. 8 briefly stalled her momentum, but she responded with two birdies against two bogeys on the back nine to finish the day tied for 14th place.

She trails first-round leader Jennifer Kupcho of the United States by just four shots heading into the second round.

Meanwhile, fellow Filipina Pauline del Rosario faced a challenging debut in the championship, carding a 78.

Kupcho made seven birdies to fire a five-under-par 66 and seize a one-shot lead.

The 29-year-old American, whose lone major victory came at the 2022 Chevron Championship, produced one of the day’s best displays of ball-striking on a course that challenged even the world’s top players. Kupcho gained more than four strokes on the field with her approach play and never appeared intimidated by Riviera’s firm greens and strategic design.

Despite missing the cut in each of her three previous US Women’s Open appearances, Kupcho looked comfortable from the start, making three consecutive birdies midway through her round before adding back-to-back birdies after the turn.

“I just really, really like the golf course,” Kupcho said. “It’s kind of a ball-striker’s paradise. Just hit it down the fairway, hit it on the green and make the putts.”

Kupcho credited a scouting trip to Riviera two months ago during the LPGA Tour’s stop in nearby Tarzana for helping her preparation.

“When I showed up this week, it was just like I knew where everything was,” she said. “I knew what I was doing. So I think it actually helped. Parents are always right, right?”

South Korea’s Sei Young Kim stayed within striking distance after carding a four-under-par 67. The 33-year-old opened with birdies on two of her first three holes before finishing strongly with three consecutive birdies over her final four holes. She capped her round by draining a 29-foot par putt to remain just one shot off the pace.

“This course is really famous in the world, so I’m very happy to play here this week,” Kim said. “Also, the course is not easy. Every hole is putting me to the test.”

A group of players shared third place at three-under-par 68, including Mexico’s Gaby Lopez, Japan’s Hinako Shibuno, and South Koreans Hyunjo Yoo, Ina Yoon and Minji Kang.

Lopez briefly reached six-under during a blistering start that featured five birdies in her opening eight holes, but three bogeys on the back nine prevented her from challenging for the outright lead.

The historic Riviera layout, celebrating its centennial year, proved every bit as challenging as expected. Although play began under overcast skies before sunshine emerged later in the day, the course yielded few low scores. Only one eagle was recorded in the entire field, with American Allisen Corpuz holing out from 86 yards with a six-iron on the 17th hole.

World No. 1 Nelly Korda endured a frustrating opening round, posting a two-over-par 73 after struggling off the tee. Korda even changed shoes during the round after testing a new pair sent by Nike and NBA superstar LeBron James, an avid golfer and longtime supporter of the American star.

“It wasn’t a great day,” Korda admitted. “I hit it really good Monday through Wednesday, so I have honestly no idea where this came from.”

Meanwhile, 16-year-old amateur Aphrodite Deng continued her rise as one of golf’s brightest young talents. The US Girls’ Junior champion was among the early contenders before settling for an even-par 70 after playing her final two holes in three over par.