Tyrrell Hatton rolled in a 20-foot putt for birdie on the final green to snatch a one-shot victory after a pulsating final round of the Italian Open in Monza.
Hatton, who successfully defended his Alfred Dunhill Links Championship title last week, looked too far back to challenge when Ross Fisher and Kiradech Aphibarnrat blitzed the Golf Club Milano course with a barrage of birdies and shared the clubhouse lead on 20 under.
But Hatton suddenly found his range with the putter as he reeled off four consecutive birdies from the 12th and, after two cast-iron pars, he clipped a solid second to the heart of the 72nd green and his putt had just enough pace to drop in the left side of the hole.
Overnight-leader Matt Wallace endured a difficult day, although he provided the shot of the tournament with an outstanding chip-in for birdie at the 17th before a par at the last saw him come up two shots short.
Tommy Fleetwood could not get himself into contention, but his faultless 67 was good enough to finish five strokes ahead of Sergio Garcia and extend his lead at the top of the Race to Dubai standings.
Wallace had a two-shot advantage after 54 holes and made a great start with a birdie at the first, but he soon found himself under immense pressure as Fisher birdied four of the first six and Aphibarnrat birdied the opening four holes to set the tone for the day.
Fisher picked up another three shots in four holes around the turn and added another at the long 14th, but he was unable to convert further chances down the stretch and four closing pars completed a sublime 63 which gave him the clubhouse lead on 20 under.
That total appeared to be at least one stroke short when Aphibarnrat surged into the outright lead with birdies at 11, 12 and 14, but the Thai powerhouse made a huge mistake at the 16th when he missed the green with his approach and chunked his attempted flop-shot into a bunker.
He did well to splash out to 12 feet from a plugged lie in the sand, but he missed the bogey putt to gift the lead back to Fisher, although he clawed one back at the next and then came within a whisker of his 10th birdie of the round at the last as he signed for a 65.
Fisher and Aphibarnrat then loitered around the Sky Zone next to the practice green as they waited for the final groups to come in, and a three-man play-off loomed as Hatton began his sensational back-nine charge.
The in-form Englishman was a picture of frustration after picking up just one birdie over the first 11 holes, but his all-round game sparked into life from the 12th as he backed up his precision long game with some precise putting.
Hatton's 30-foot putt for a fourth straight birdie at the 15th teetered on the edge of the cup before dropping a few moments later and, after an assured two-putt from long range at the penultimate hole, he found the fairway at the last and knocked a pure second to 20 feet.
And a day after celebrating his 26th birthday, Hatton judged the pace and line to perfection to make it back-to-back victories which sealed the $1.16m first prize in the fifth of the Rolex Series events, while he can also look forward to returning to the world's top 20 when the rankings are updated on Monday.
Wallace had to settle for outright fourth after an errant display on the tee, and the Englishman was left to rue a huge error on the par-five 14th as he ran up only the second bogey-six of the entire day on that hole.
He looked a forlorn figure when he went long and left with his approach to the 17th, but he opted to play a bump-and-run with a high degree of difficulty and prompted the loudest cheer of the day from the passionate galleries when his ball cannoned into the pin and dropped for a remarkable three.
However, Wallace then blocked another drive right at the last and could not find the green with his second, although he did produce an excellent up-and-down from the sand to return a 69 and pocket the biggest cheque of his career.
Marcus Fraser stormed to the turn in 30 but offset two more birdies with a pair of bogeys on the back nine as a 65 left him three off the pace and one ahead of Fleetwood, George Coetzee, David Horsey and local hero Francesco Molinari.
The defending champion was given a rapturous reception on his arrival on the first tee, but he failed to reproduce the form that swept him to a popular victory last year, although birdies at three of the last five holes salvaged a respectable 69.