PÁdraig Harrington went into the competition ranked 297th in the world, but came out on top with $1m in his back pocket.
The 43-year-old fended off America's Daniel Berger in a thrilling play-off at the Honda Classic PGA National in Florida yesterday afternoon, securing his first win on American soil since the 2008 PGA Championship.
The ever calm father of two visited American fast food emporium Five Guys shortly after his golden comeback on the course and he shared a picture of his "first celebration meal" on social media.
There were tributes to the Dublin native from a host of Ireland's sporting legends, as well as Taoiseach Enda Kenny.
Mr Kenny took to Twitter to extend his congratulations to the triple Major winner, writing: "Form is temporary, class is permanent. Good man Pádraig Harrington."
Golfing legend Christy O'Connor Jnr described the win as a "magnificent victory".
"It was brilliant, he never went away. It just shows what this guy has got in store," Mr O'Connor told the Irish Independent. "People were telling him his head was gone, it was awful.
"I watched every single minute. I thought the 17th hole was a bad hit for him, but that putt was great. I'm so proud of him."
He added: "What a week for Ireland; I backed him at 10-1 at 9pm on Sunday night as well."
Golfing legend Des Smyth acted as vice-captain for the victorious European side alongside Harrington at last year's Ryder Cup in Scotland.
He paid tribute to the two-time British Open champion's "determination" after being "worried for him" in recent times.
"We are all delighted. Never give up on the fact that he is going to make a comeback, because Pádraig always believes in himself. He knows how to dig deep," Smyth said.
"When he hit the water at the 17th hole I was nervous for him, it was typical him - he likes to do it the hard way.
"He went through a bad patch but the week I spent in Gleneagles with him, he was very positive about his game."
Golfer Shane Lowry also extended his congratulations last night, declaring the "legend" is "the best Irish sportsperson of all time".
Harrington is expected to rise to 82nd in the world rankings.