Phil Mickelson Wins the P.G.A. Championship

KIAWAH ISLAND, S.C. — With a victory at the P.G.A. Championship on Sunday, Phil Mickelson, who will turn 51 next month, became the oldest golfer to win a major championship. The oldest previously was Julius Boros, who was 48 when he won the 1968 P.G.A. Championship.

Mickelson shot six under par for the tournament, finishing two strokes ahead of the runners-up, Brooks Koepka and Louis Oosthuizen.

It was Mickelson’s sixth major title, something only 14 male golfers have achieved. Mickelson was the seventh to reach that total since 1964. Mickelson has won the Masters tournament three times and was the British Open champion in 2013. Sunday’s victory was his second P.G.A. Championship title. He has finished second at the United States Open six times.

This year’s P.G.A. Championship, contested over four days at the treacherous Ocean Course on Kiawah Island, was a bedeviling test with gusty, seaside winds altering the flight and outcome of hundreds of shots. Mickelson began Sunday’s round with a one-stroke lead over Koepka, a four-time major winner.

Mickelson’s victory was not foreshadowed by his recent performances in other events. Since missing the cut at last year’s United States Open, his best result in a PGA Tour event had been a tie for 21st. He finished outside the top 50 nine times.