Clarke was steady through all four stages of the tournament, never finishing lower than sixth on any respective day. The 42-year-old Irishman shot even on Sunday, maintaining his 5-under score.
Mickelson, who started the day tied for seventh, got off to a hot start early on, quickly moving up the leaderboard towards Clarke. An eagle on the seventh gave Mickelson, whose last major championship win was the 2010 Masters, a share of the lead. Mickelson let off though, finishing the day at only 2-under.
Clarke, grouped in the final pairing, maintained his consistency and did not falter. He answered Mickelson with an eagle of his own on the seventh, giving him a sizable lead that he would not relinquish.
American Dustin Johnson, who entered the day three strokes behind Clarke for second place, shot 2-over, placing him in a tie with Mickelson for second. On the 14th, Johnson found himself within two strokes of the leader, but hit the ball out of bounds and finished the hole with a double-bogey. Rory McIlroy, winner of the U.S. Open, finished in 25th place.
