Five-time major winner Phil Mickelson defeated Justin Thomas in a play-off after an extraordinary climax to the WGC-Mexico Championship to claim his first victory since the 2013 Open.
Mickelson parred the first extra hole to become, at the age of 47, the oldest winner of a World Golf Championship event and secure the 43rd title of his career.
Thomas failed to get up and down from the back of the 17th green, the same hole he had three-putted in regulation to kick-start a remarkable sequence of events.
The US PGA champion, who won the Honda Classic in a play-off eight days earlier, then holed his approach to the 72nd hole for an eagle two to set a clubhouse target of 16 under par which looked difficult to catch.
But England's Tyrrell Hatton also reached 16 under thanks to birdies on the 12th and 14th and an eagle of his own on the 15th, while playing partner Mickelson birdied the 15th and 16th to make it a three-way tie.
That tie was broken when Hatton bogeyed the final hole of regulation and meant the 26-year-old had to settle for a share of third with Spain's Rafa Cabrera Bello, who had birdied the same hole in his closing 67.
Mickelson and Thomas headed back to the par-three 17th for sudden death and after Mickelson's birdie attempt had agonisingly grazed the edge of the hole, Thomas missed from 10 feet for par.
Thomas had been 11 shots off the lead at the halfway stage of the £7.2million event, but carded a course record of 62 in the third round and a brilliant closing 64, with Mickelson shooting a final round of 66.
"I can't put into words how much this means to me," Mickelson, who had finished fifth, second and sixth in his previous three starts, told Sky Sports.
"It's been a long time and to come through here in Mexico City, with the fans here and to play against the best players in the world and finally come through... I knew it was going to be soon, I was playing too well for it not to be, but you just never know until it happens.
"To be able to share this with my family, my brother (his caddie Tim) and everybody really means a lot, especially knowing all the tough times we've had the last four years."
Asked about the upcoming Masters, a major title he has already won three times, Mickelson added: "My game's starting to get to a level that is some of my best golf and it seems like it's just in time."
Thomas told the European Tour website it was "pretty unbelievable" he had even had a chance of winning.
He said: "I'm really proud of myself how well I played, how I hung in there, how I even had a chance to win. Obviously the play-off didn't go how I wanted but I'm happy for him and proud of him. He's really been working hard to get back in the winner's circle, and it was a great week for both of us.
"I putted pretty well this weekend. I made some putts and that's what you have to do to shoot 16 under on a weekend. We had a chance and that's all I could ask."
Hatton, meanwhile, spoke of his frustration at not being in the play-off, but admitted it "just wasn't meant to be".
He said: "You never know when you're going to get the chance to win a WGC event again. This is the first chance I've had of winning.
"I can't believe that I'm not at least in the play-off - I've played good enough, thought I handled the situation pretty well. Guess it just wasn't meant to be.
"You don't get many opportunities to win WGC events and I feel like I've thrown a really good opportunity away. So I'm pretty upset, definitely angry."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules here