Rising Australian golf star Cassie Porter has fallen short in her quest to claim a maiden LPGA Tour triumph in America.

Reigning women's British Open champion Miyu Yamashita instead won the $US4.65 million ($A6.63 million) Meijer Classic in a play-off from faltering English star Lottie Woad on Sunday (Monday AEST).

Woad looked home and hosed after holing out from a greenside bunker for birdie on the 17th hole to capture the solo lead.

But to gasps of disbelief, the 22-year-old missed a putt from inside two feet on the last to invite Yamashita back into the contest.

Japan's 2025 LPGA Tour rookie of the year Yamashita duly prevailed with a birdie on the first extra hole to complete a phenomenal Sunday comeback.

After starting four shots behind US third-round leader Jing Yan, Yamashita fired a birdie-filled eight-under-par 64 at Blythefield Country Club in Michigan.

Woad joined Yamashita at 17 under after closing with a 68, the pair finishing two shots clear of China's Yan Liu (67) and Taiwan's Wei-Ling Hsu (67). 

"I didn't think about like win today," Yamashita said. "I just focused on playing just like every round. My putting was solid today and I was able to put together a really good round.

"I really didn't expect like it's going to be playoff, but once it did, I was able to reset mentally and focus on the task at hand.""

With a final-round 70, Porter had to settle for a tie for fifth with South Korean Minji Kang (66).

The 23-year-old Sydneysider started the day only two strokes off the pace, but made a deflating start with two bogeys in her first three holes.

Porter fought back with four mid-round birdies to eventually notch a second-straight top-10 finish and third of an ultra-consistent second year on the world's biggest tour.

Fellow Australian Grace Kim charged home with a six-under 66 to finish one shot further back in a tie for seventh with Jing, who faded with a 73.

Yamashita won for the third time on the LPGA Tour after winning 13 times on the JLPGA. Last year, she won the Maybank Championship and major Women's British Open and was the LPGA rookie of the year.

The major KPMG Women's PGA Championship begins Thursday at Hazeltine in Minnesota.