Edoardo Molinari became Italy's first winner of the US Amateur Championship thanks to a 4&3 victory over Dillon Dougherty at Merion, Pennsylvania.
Molinari made just 18 putts in the 15 holes of the second round
The 24-year-old looked to be heading for defeat after being three down after the first 18 holes.
But the engineering student fired seven birdies in the 15 holes of the second round to seal victory.
"All of a sudden the putts went in this afternoon instead of this morning," Molinari said.
Dougherty was never behind in the opening 18 holes and had three birdies to take charge of the contest.
But Molinari birdied the first two holes of the second round and then had a one-putt par at the 23rd hole to draw level.
A birdie nine-foot putt at the 25th put him ahead for the first time and it was a lead he never relinquished.
The win was sealed at the 27th and 29th when he fired in birdie putts of more than 30 feet while another lengthy putt at the 33rd closed out the win.
"I played pretty good in the afternoon, but he just played unbelievably," said Dougherty.
"A lot of times that's just what it comes down to, who makes the putts. When he made a lot of those putts, I was inside him and I ended up missing."
Both Molinari and Dougherty earn exemptions into next year's US Masters and US Open, as long as they retain their amateur status.