Michio Matsumura held off a final round charge by Kim Do-hoon on Sunday to beat the South Korean in a playoff and win the Casio World Open.
The 27-year-old Matsumura carded a final-round 4under 68 and returned to the clubhouse looking on course to win the tournament in regulation play.
However, Kim, who had shot successive 70s in the previous three rounds, climbed up the leaderboard with five birdies through 15 holes without dropping a shot over the par-72 layout at Kochi Kuroshio Country Club.
The 21-year-old then picked up shots on the 17th and 18th to finish with a superb 7-under 65 -- the best round of the day -- and alongside Matsumura on 13 under 275 to force a playoff. But Kim sent his second shot from the rough out of bounds on the fourth playoff hole and conceded victory when Matsumura hit his third shot inches from the pin.
The victory was Matsumura's second of the season after winning last month's Tokai Classic.
Kim Hyung-tae shot a 69 to finish in third, while Katsumasa Miyamoto carded a 71 to take fourth place.
Ryo Ishikawa -- second on the Japan Golf Tour's money list -- carded his best round of the tournament with a 68 to tie for eighth.