Akie Iwai fired six birdies in a 6-under par 66 to win the Portland Classic by four strokes and join twin sister Chisato as a first-time LPGA winner in their rookie season on the U.S. tour.

Akie Iwai started the day at Edgewater Country Club with a two-stroke lead and never faltered to finish with a 24-under par total of 264.

Chisato Iwai was among the golfers trying to apply pressure, charging up the leaderboard with an 8-under par 64, but it was American Gurleen Kaur who finished second after an impressive, bogey-free 7-under par 65 for 268.