Saigo sank a tension-packed birdie putt on the 18th hole in regulation to fire a final-round two-over par 74 at Carlton Woods and finish 72 holes on seven-under 281 just to reach the playoff.
At the 18th again in the playoff, Saigo sank a four-foot birdie putt to capture the crown after clutch putt misses by her rivals.
Saigo, a 23-year-old who was last year’s LPGA Rookie of the Year, defeated China’s Yin Ruoning, South Korean Kim Hyo-joo, Thailand’s Ariya Jutanugarn and American Lindy Duncan in the playoff.
“This is like dreaming,” Saigo said through a translator. “It was my big dream and goal this year. I still can’t believe it.”
“It means a lot that I made a birdie putt on 18. That gave me more confidence for the playoff,” she added.
The playoff was at the par-five 18th and Yin reached the green in two by blasting over a water hazard. Saigo and Ariya each went over the green with their second shots, Duncan was short of the green in three and Kim found the green near Yin’s ball with her third shot.
Ariya and Saigo missed their eagle bids, setting the stage for Yin’s eagle attempt to win from about 12 feet. It went eight feet past the hole as tension mounted.
Kim missed her birdie putt, Duncan missed a 10-foot par putt and tapped in for bogey, then Yin lipped out a birdie putt and tapped in for par.
Ariya lipped out on her eight-foot birdie putt and tapped in for par, leaving Saigo to sink her four-foot birdie for the triumph.
Ariya had botched a chip on the 72nd hole in regulation and made a bogey that dropped her into a share of the lead, helping to deny her a third major victory and first in seven years.
Yin and Kim each sought a second career major while Duncan settled for her first top-10 major finish.
Ariya led by a stroke at the 18th tee in regulation and blasted her second shot from the fairway over the green and off the grandstand.
Stunningly, she then miss-hit a chip from the rough that barely moved the ball before sending her fourth shot 15 feet beyond the hole. She missed the comeback attempt and made bogey.
That dropped her to seven-under and into a share of the lead with Yin, who birdied the 18th, and Kim in the clubhouse.
Saigo and Duncan each needed a birdie at 18 to share the lead.
South Korea’s Ryu Hae-ran, their playing partner, holed out a chip for the first eagle of the week at 18. Neither Duncan nor Saigo could match her, but each made a birdie putt to reach the playoff.
Saigo and South Korea’s Ryu shared the lead entering the final round but Ariya, who started three adrift, closed the gap with a birdie at the second hole and an eagle at the par-five fourth.
Ryu fell back with four bogeys in the first six holes but Saigo had two birdies and two bogeys in the first eight holes and shared the lead with Ariya at nine-under.
Saigo began the back nine with back-to-back bogeys, falling two back, but Ariya made bogey at the par-five 13th that trimmed her lead to one.
Duncan shook off a bogey at the par-three 12th with a birdie at 13 and sank a four-foot birdie putt at 14 to grab a share of the lead, but stumbled with bogeys at 15 and 16. (AFP)
