Collin Morikawa overcame Justin Thomas in a play-off to win the Workday Charity Open, his second title on the PGA Tour.
In just his 24th start as a professional, Morikawa capitalised on a late collapse by Thomas to join his fellow American in a share for top spot after 72 holes – the pair locked together at 19 under par.
There was nothing to split them when they twice played the 18th again, both managing an opening birdie before Thomas missed a putt for victory.
Having moved to the 10th, Thomas quickly found trouble off the tee and, forced to pitch out, handed the advantage to his rival. Morikawa duly seized the opportunity, collecting the par he needed to prevail at the third extra hole.
Former world number one Thomas had held a two-shot lead overnight having produced three bogey-free rounds at Muirfield Village.
While Thomas dropped shots at the second and third in a shaky start to his Sunday, a run of four birdies around the turn had the world number five back on track for victory.
An eagle at the 15th pushed Thomas three clear, yet he bogeyed two of his final three holes to sign for a score of 69, only enough to tie with Morikawa after the 23-year-old had risen up the leaderboard with his 66.
Viktor Hovland (71) finished alone on 15 under, his hopes for a late charge dashed by a one-over back nine, with Chase Seiffert (67) was a further shot back.