Shane Lowry defeated the elements and his rivals in stunning fashion to become a major winner for the first time, recording a commanding six-shot victory for an emotional Open Championship triumph at Royal Portrush.
A day after he emerged from a bunched pack in a spectacular finish to round three, Lowry held his nerve to triumph by a distance on 15 under par, shooting a one-over 72 amid constantly changing conditions that included severe rain on the Dunluce Links.
Tommy Fleetwood, who started four back on Sunday, could not get going with the putter despite some handy looks for birdie early in his round and the Englishman struggled to a 74 that left him six behind the champion.
Lowry had reached a low point 12 months ago at the same tournament at Carnoustie, where he missed the cut - for the fourth Open in succession - and slipped to 92nd in the world rankings.
Yet this victory, the first in a major with a margin of five or more strokes since Rory McIlroy's U.S. Open triumph at Congressional in 2011, was just reward for four days of sublime golf played with the backing of a vociferous crowd desperate for an Irish winner on Irish soil.
It marks a crowning moment in Lowry's career three years on from him letting a four-shot lead slip in the final round of the U.S. Open at Oakmont.
His success owed much to a fantastic eight-under 63 on Saturday when the glorious conditions were in stark contrast to the heavy downpours and high winds that greeted the leaders the following day.
The landscape of the leaderboard could have been markedly different after the first hole the final pairing played in the fourth round, when Lowry followed a nervy tee shot that landed in the left rough with an approach into the greenside bunker, while Fleetwood put his approach to within 10 feet.
Lowry limited the damage, though, recovering to make bogey as his nearest rival missed a presentable birdie chance.
An increasingly assured Lowry duly extended his lead with a run of three birdies in four holes to reach 18 under through seven and, even when the weather worsened to make scoring difficult, his lead never really came under threat thereafter.
Three dropped shots between the eighth and 11th did little damage, with Fleetwood also dropping shots in the damp conditions.
A birdie at 12 brought Fleetwood within four, but a double-bogey six at 14 killed any hope of a comeback and another birdie for Lowry at 15 brought huge cheers.
The chasing pack below Lowry and Fleetwood only fleetingly threatened any sort of charge, with Lee Westwood the only man bar the leaders to reach 10 under at any stage on Sunday.
Westwood ultimately finished in a tie for fourth with world number one Brooks Koepka at six under, with Tony Finau one shot better off in third after a level-par 71.
Last year's Open champion, Francesco Molinari, carded a 66 before the poor weather arrived to share 11th at three under. It was a very different story for JB Holmes, playing with Koepka in the penultimate group, who shambled to an 87.