American Webb Simpson has won the U.S. Open golf tournament, shooting a 68 in the final round to claim his first major championship.

Simpson watched from the clubhouse after his 2-under-par round Sunday at the Olympic Club in San Francisco as a pair of golfers tried to match his score. American Jim Furyk and Graeme McDowell of Northern Ireland — both previous U.S. Open winners — each had a chance to catch Simpson on their final hole, but fell short.

Simpson began the day four shots off the lead, but rallied with four birdies in five holes to move into contention. He parred the final eight holes to win the tournament by a single stroke, finishing at 1-over-par 281.

He said the string of birdies was the “difference” on Sunday. Simpson “got off to a slow start” with two early bogeys, but said he knew there were opportunities for better scores later in the round and that he had to “stay patient.”