Brooks Koepka became the seventh man to win back-to-back US Open titles after overcoming a testing and controversial week at Shinnecock Hills.
The 28-year-old Floridian beat England's Tommy Fleetwood by one shot with world No.1 Dustin Johnson two back and Masters champion Patrick Reed three adrift.
Koepka is the first player since Curtis Strange in 1988 and 1989 to win back-to-back US Open titles.
Despite having at least a share of the lead at the end of each of the first three rounds, Johnson was unable to add a second US Open title to 2016's breakthrough major win.
Fleetwood took advantage of the USGA's kinder set-up following a controversial Saturday to shoot only the sixth 63 in US Open history 45 years after Johnny Miller posted the first in 1973 at Oakmont.
Phil Mickelson was back a day after sparking the "putt-gate" controversy when he hit his still moving ball back towards the hole. The left-hander, who improved on Saturday's 81 with a closing 69 to end +16, declined to offer any further comment on the incident.
Day three: Birthday boy Phil Mickelson (48) sparked controversy as he ran after a still moving putt and hit it back towards the hole. Mickelson later said he was fed up with going back and forth and "you take your two-shot penalty and move on." He denied he was being disrespectful.
Mickelson's playing partner Andrew Johnston said he had never seen a situation like that before. "His body acted quicker than his brain," he told BBC Radio 5 Live.
Dustin Johnson led by four overnight but endured some mid-round demons before fighting back. The world No.1 goes into Sunday's final round in a four-way tie for the lead with Brooks Koepka, Daniel Berger and Tony Finau.
American Daniel Berger shot a four-under 66 in favorable conditions Saturday morning and jumped up the leaderboard when the later starters struggled in stronger winds.