Kohki Idoki came from relative obscurity, and five shots back, to win the Senior PGA Championship by two strokes on Sunday.
Idoki, making just his second career Champions Tour start, fired a 6-under 65 at Bellerive Country Club, supplanted overnight-leader Kenny Perry, and secured his first-ever major championship victory.
The 51-year-old Japan native, who went ahead for good with a lengthy birdie putt on the 17th, ended at 11-under-par 273, two strokes clear of Perry (72) and Jay Haas (70).
"I didn't imagine I would win until the third round," Idoki said through a translator. "But I continued playing my best all week ... I can't believe that I am the champion."
Perry was seeking his third career victory and first major title on the Champions Tour. He led by three strokes for much of the final round, but stumbled to a double-bogey 5 on No. 13, which allowed Idoki to pull even, and later fell from contention with back-to-back bogeys from the 16th.
Mark O'Meara (65) jumped 11 spots into a solo fourth finish at 8-under, Kiyoshi Murota (67) took fifth at 7-under, and Jim Rutledge (64), Kirk Triplett (68), Duffy Waldorf (69), Russ Cochran (72) and Rod Spittle (71) tied for sixth at minus-6.
Perry recorded three straight rounds in the 60s to begin this tournament, the only player in the field to do so, and he carried the momentum into the final round with a trio of birdies over his first five holes.
That run gave Perry a 3-stoke lead, but the 52-year-old couldn't maintain the momentum. He tripped to a bogey on the sixth, then parred six straight holes, opening the door for the unlikely challenger.
Idoki crept into contention with four birdies during a bogey-free outward 32, then stayed within striking distance by opening his back nine with four consecutive pars.
The crucial swing came when Perry found the sloped rough at the par-3 13th, chipped on, and 3-putted for double bogey as Idoki, playing two groups ahead, wrapped up a birdie on the 14th and moved into a share of the lead.
"I had 200 to the back and I hit a 6-iron and it flew the whole green," explained Perry. "That kind of shell shocked me a little bit. I couldn't believe it went that far, for one thing. And then I was in jail the whole time. So to make double on a hole that you think you can make birdie on, or at least par, that hurt."
The pair remained tied until Idoki rolled home a 15-foot, downhill birdie putt on the 17th to go up by one at 11-under. Then, as the Osaka resident drilled his drive into the fairway on the tournament's 72nd hole, Perry missed a par putt on the No. 16, stretching the margin to two.
Perry found more trouble on the 17th, sending his drive into the trees and settling for another bogey as Idoki calmly tapped in for par at the last to wrap up his sparkling 65.
"I was surprised to tear up when I was putting for the win," continued Idoki. "I was surprised also with the huge galleries on the course. I was very excited."
A birdie on the last moved Perry into a tie for second with Haas, who closed with back-to-back birdies.
NOTES: Idoki is the first player from Asia to win a major title on the Champions Tour. With the win, Idoki earned a full one-year exemption on the tour. He also earned a berth in the 2013 PGA Championship at Oak Hill Country Club ... Haas is a two-time winner of this event ... Jeff Coston and Mark Mielke tied for the low club professional at even-par 284.