BROOKS Koepka produced a back-nine birdie blitz to win the US Open, becoming the seventh consecutive first-time winner of a major with a record-equalling victory at Erin Hills by four strokes.
The 27-year-old from Florida fired a five-under-par final round 67 to finish on 16 under for the tournament following a tense duel with compatriot Brian Harman that was settled on the home stretch at the rural Wisconsin course.
Koepka's 16-under-par total equalled the record for the lowest winning under par total at a US Open set by Rory McIlroy at the 2011 championship.
Third round leader Brian Harman, who had led by one-shot at the start of the round, finished second on 12 under after an even-par 72. He tied with Japanese world number four Hideki Matsuyama who shot a superb six-under-par 66.
England's Tommy Fleetwood was alone in fourth place on 11 under after a level-par final round of 72.
Harman and Koepka spent much of the round locked at the top of the leaderboard.
But the turning point in a gripping war of nerves came just after the turn when Harman struggled through back-to-back bogeys on the 12th and 13th.
World number 22 Koepka then uncorked a brilliant trio of birdies on the 14th, 15th and 16th holes to surge into a four-shot lead and virtually assure himself of the title.
Koepka's win extended a remarkable run of victories by players who had never previously won a major.
Since Jason Day lifted the 2015 PGA Championship, every major championship has been won by a first-timer.
Koepka, a close friend and training partner of world number one and 2016 US Open champion Dustin Johnson, had only won one title on the PGA Tour since turning professional in 2012.