The Iwai twins' incredible season continued as Akie joined sister Chisato on winning on the LPGA Tour as a rookie as she eased to the Portland Classic.
Back in May, Chisato came up trumps the inaugural Mexico Riviera Maya Open thanks to a final-round 66 to win by six shots and this time around, her twin also posted a final-day 66 to finish on 24-under par, four clear of American Gurleen Kaur who had been stalking the summit all week.
The Japanese golfer went bogey free, finishing with back-to-back birdies to confirm her first win on the LPGA Tour.
First to congratulate her was her twin Chisato who finished in a tie for third with Sweden's Linn Grant after a stunning 64 – a score only matched by American amateur Kiara Romero.
They are fourth set of sisters to win on the LPGA Tour, joining Jessica and Nelly Korda, Ariya and Moriya Jutanugarn and Annika and Charlotta Sorenstam.
Antrim's Stephanie Meadow missed the cut after a second-round 77.
