Xander Schauffele carded a flawless closing 65 at Royal Troon to finish nine under par and win his second major title in quick succession in the 152nd Open, which completed an American clean sweep of the sport's Majors.
He was two shots clear of overnight leader Billy Horschel and Justin Rose, who had threatened to become the first English winner of the Claret Jug since 1992.
South Africa's Thriston Lawrence, who held the lead after 11 holes of the final round, finished a shot further back in fourth following a 68.
"I just can't wait to drink out of it," Schauffele said as he cradled the Claret Jug. "It really is a dream come true to be holding this.
"It means a lot, it's something all of us play for. It definitely hasn't sunk in yet and I can't wait to sit back and have a moment with this Claret Jug."
Schauffele, who registered a major record of 21 under par to win the US PGA at Valhalla in May, is the first player to win two majors in a year since Brooks Koepka in 2018.
The world number three is also the seventh American winner in the last eight Opens at Royal Troon – Sweden's Henrik Stenson having denied Phil Mickelson in a thrilling duel in 2016 – and will head to Paris to defend his Olympic title in brilliant form.
Schauffele, who has now finished no worse than 18th in his last 10 starts, was eighth in the Masters and seventh in the US Open either side of his US PGA triumph, where he birdied the 72nd hole to edge out Bryson DeChambeau by a shot.
"I thought it would help me and it did, I had this sense of calm that I didn't have playing the PGA," Schauffele added.
"I said to my caddie Austin (Kaiser) I felt calm on the 18th tee and he said he felt like he was about to puke."
Rose was bidding to become the first qualifier to lift the Claret Jug since Paul Lawrie in 1999, while the 4,053-day gap since his 2013 US Open victory at Merion would have set a new record.
The prospects looked good when Rose birdied the second and fourth to overhaul Horschel and again when he birdied the eighth, only for a bogey on the 12th to halt his momentum at just the wrong time.
Playing alongside Horschel, Lawrence was reaping the rewards for an aggressive approach as birdies on the third, fourth, seventh and ninth gave him the lead before Schauffele, who had covered the front nine in 34, produced a decisive burst.
A stunning approach to the 11th left Schauffele with a tap-in for the only birdie all day on the daunting par four, another on the 13th took him into a share of the lead and Lawrence's bogey on the 12th handed Schauffele an advantage he would never relinquish.
Further birdies on the 14th and 16th gave Schauffele the luxury of a three-shot lead and he completed a nerveless display with pars on the final two holes before Rose birdied the 18th to round off a superb 67.
Horschel birdied the 16th, 17th and 18th to join Rose in second, with Lawrence another shot back after saving par on the last despite hitting his second shot into the face of a bunker and watching it fly back over his head onto the fairway.
Ireland's Shane Lowry, who held a two-shot lead at the halfway stage before struggling to a 77 on Saturday, shot 68 in the final round to finish sixth, with Jon Rahm, Sungjae Im and Scottie Scheffler three strokes further back in seventh.
Masters champion and world number one Scheffler had been within two of the lead until amazingly four-putting the ninth for a double bogey.
