On June 17, Simpson won the U.S. Open at the Olympic Club in San Francisco. He shot a two-under 68 in the final round for a final score of one-over par. It was good enough to win by one stroke over Graeme McDowell and Michael Thompson. McDowell missed a 25-foot birdie putt on the 18th hole that would have forced a playoff. It was Simpson's first major championship win. The win moved Simpson to a career-high fifth in the Official World Golf Ranking.