Brooks Koepka became the first U.S. Open champion in 29 years to successfully defend his title when he clinched a one-stroke victory on Sunday.
Koepka staved off a brilliant charge by Englishman Tommy Fleetwood, who matched the lowest score in tournament history, a seven-under-par 63 at Shinnecock Hills.
Koepka shot a closing 68 to finish at one-over 281 and become the first to win back-to-back since Curtis Strange in 1988 and 1989.
After admitting they went "too far" with their course set-up for round three, USGA officials applied "appropriate levels" of water to the greens at Shinnecock Hills on Saturday night and Sunday morning, as well as selecting some more favourable pin positions.
Fleetwood took full advantage with a stunning final round of 63, agonisingly missing from eight feet for birdie on the 18th to equal the all-time major record of 62 set by Branden Grace in last year's Open Championship at Royal Birkdale.
The 27-year-old's score still matched the lowest in US Open history and set a testing clubhouse target on two over par, with Koepka and Masters champion Patrick Reed sharing the lead on one over with 11 and 10 holes to play respectively as Fleetwood signed his card.
Reed's bid to claim the second leg of the calendar grand slam faltered with three bogeys in four holes around the turn, Koepka moving two ahead with a birdie on the 10th before scrambling to salvage a bogey on the next after firing his tee shot over the green and his second into a greenside bunker.
Koepka also crucially saved par on the 12th and 14th before striking the killer blow, a superb approach to the par-five 16th setting up a tap-in birdie.
That allowed the 28-year-old the luxury of a bogey on the 18th and he eventually signed for a 68 to finish one over par and just a shot ahead of Fleetwood, with world number one Dustin Johnson a stroke further back.