DeChambeau edges McIlroy by one stroke to win US Open
The 30-year-old American, who also won the 2020 US Open, fired a one-over-par 71 to finish on six-under-par 274 while McIlroy shot 69 to stand on 275 after 72 holes.
McIlroy, thwarted in a bid to end a 10-year major win drought, led by two strokes with five holes to play.
But the four-time major winner from Northern Ireland made bogeys on three of the last four holes to help hand the trophy to DeChambeau.
In a collapse mindful of Greg Norman's epic 1996 last-round loss to Nick Faldo at Pinehurst, McIlroy missed par putts from 2.5 feet at the par-3 17th and just inside four feet at the par-4 18th -- tension-packed misses for bogeys that left McIlroy one behind.
DeChambeau found dirt and weeds left and a bunker at 18 but blasted his third shot to four feet and sank his pressure-packed putt for the victory.
Raising his arms in triumph, DeChambeau screamed and jumped for joy, then paid tribute to the late Payne Stewart, the 1999 US Open winner at Pinehurst who died only a few months later.
"That's Payne right there, baby," DeChambeau said into a television camera, pointing to a pin of Stewart on his cap.