American Billy Horschel condemned golf's self-proclaimed "nearly man" Rory McIlroy to another heartbreaking defeat in the BMW PGA Championship at Wentworth.
Horschel eagled the second play-off hole to win the DP World Tour's flagship event for the second time in four years after he, McIlroy and South Africa's Thriston Lawrence had finished tied on 20 under par.
Lawrence was eliminated on the first extra hole after seeing his third shot spin back off the green and into the water, with McIlroy and Horschel both making birdie.
The players returned to the par-five 18th for the second extra hole and both found the green in two, McIlroy narrowly missing his eagle attempt from around 30 feet before Horschel holed from marginally closer.
McIlroy labelled himself a "nearly man" after finishing fifth in the Olympics in Paris, blowing his chances of a medal when he hit his approach to the 15th into the water.
The world number three had also bogeyed three of the last four holes in June's US Open to miss out on a first major title since 2014 and last week narrowly failed to eagle the 72nd hole to force a play-off in the Irish Open after three-putting the 17th.
"Last week was a tough one but I left there with my head held high with the way I played the last hole trying to make three," McIlroy said after a closing 67.
"And today I played the play-off holes perfectly, really, a couple of birdies. But it just shows the standard out here. If you slip up just a little bit or don't make a birdie on a crucial hole, someone is always waiting to take advantage of that.
"Two weeks in a row I've played well. Just not quite well enough. The game is testing me a little more than it has done in the past, but that's fine.
"If someone had of said you're going to turn up at Wentworth this week and shoot 20 under par, I'd take that. All I can do is keep showing up and trying to play the golf that I've been playing and sooner or later it's going to end up in a win.
"It could have been a different year but the nice thing is there's next year and the year after and the year after and the year after. If you think of my career as a 30-career journey, it's only one year in a 30-year journey, and hopefully the other 29 are a little more productive or a little bit better."
Horschel's chance of victory looked to have disappeared when he bogeyed the 15th, but he birdied the 17th and 18th to complete a closing 67 and force his way into the play-off.
"My heart was pounding on the last couple of shots, the last couple of holes, and especially in the play-off but it's always fun being in those situations," Horschel said.
"That's what I've worked so hard for, and that's what I've always wanted to be, in situations like that, going against the best players in the world. I was able to nip Rory and Thriston and come away with the victory.
"I'm thrilled, excited for the way I played and battled out there today but at the same time a little disappointed. Rory's a really good friend of mine and I think the world of him.
"I think he's a generational talent and I know how close he's been this year so I can feel for him, but at the same time I'm pretty excited to be able to get it done today.
"It's always one of my most special weeks of the year. I enjoy coming here. I feel a sense of ease. I feel a sense of calm. I know I'm not from the UK or London or England, but I feel almost at home when I come here.
"I have a lot of friends that I've made over the years and I will say the crowds here make me feel like I'm one of their own, and I'm very appreciative of that."
Lawrence, who remarkably chipped in for birdie on the first and second, appeared to have the title in his grasp when he picked up his seventh shot of the day on the 16th, but played the last two holes conservatively and ultimately paid the price.
Italy's Matteo Manassero took a three-shot lead into the final round but could only card a closing 73 to finish in a tie for fourth with England's Matt Baldwin and Aaron Rai, with Rai's chances disappearing when he hit his approach to the last into the water.
