South Korea's Jin Young Ko shot a 3-under 69 on Sunday to win the rain-shortened Cambia Portland Classic by four shots.
Ko finished at 11-under 205, comfortably ahead of South Korea's Jeongeun Lee and Australia's Su Oh. Both golfers shot 69 Sunday.
The event was shortened to 54 holes after Saturday's third round at Oregon Golf Club at West Linn, Ore., was washed out due to heavy rain.
The 26-year-old Ko shot a bogey-free round on Sunday to win her ninth career LPGA event. It was her first tour appearance since the Tokyo Olympics.
"I had a lot of practice with my coach and had a lot of workouts," Ko said of spending approximately six weeks in South Korea. "I had a great week this week and I'm so happy for the name on the trophy. It's a great win."
Ko carded three birdies while winning for the second time this season. She also won the Volunteers of American Classic in early July.
"I tried to make a no bogey-free round today, (and) I made it," Ko said. "I had a lot of missed shots and I had a lot of missed chipping or something, so I had to make great par saves, but I made it."
Lee shot eagle-3 on the 18th hole to move into the tie for second. She recorded three birdies and two bogeys.
Oh registered four birdies and one bogey in her round.
"A few more putts drop then I would have been closer," said Oh, "but still pretty happy with how I played this whole week."
Perrine Delacour of France shot 69 to finish fourth with a 5-under 211. She had four birdies and one bogey.
"We got lucky for sure with the weather," Delacour said. "I played really solid all week long. I like the track of this course, it's really good. It's a challenging course."
Thailand's Patty Tavatanakit (69 on Sunday), Germany's Esther Henseleit (70) and Spain's Carlota Ciganda (73) tied for fifth at 4 under.
Americans Jennifer Kupcho (68) and Jennifer Song (68), South Africa's Ashleigh Buhai (69), Netherland's Anne van Dam (71), South Korea's Jeongeun Lee6 (73), Thailand's Pajaree Anannarukarn (73) and Scotland's Gemma Dryburgh (76) tied for eighth at 3-under 213.
Dryburgh was in second place after 36 holes, one shot behind Ko.