Phil Mickelson became the oldest golfer to win a major championship, shooting a last-round one-over-par 73 to capture the PGA Championship by two shots at Kiawah Island. "This is just an incredible feeling because I just believed that it was possible but yet everything was saying it wasn't," Mickelson said. "I hope that others find that inspiration. It might take a little extra work, a little bit harder effort to maintain physically or maintain the skills, but gosh, is it worth it in the end." At 50 years, 11 months and three days, Mickelson wiped out the mark of oldest winner of a major that was set by Julius Boros, then 48, in the 1968 PGA Championship. Mickelson earned his sixth major title, a list that also includes the 2005 PGA Championship. His most recent victory in a major was the 2013 British Open. He has been a major champion in three different decades. "What an achievement to win a major at 50 years old, and he deserves all of that," said South African Louis Oosthuizen, who shared the runner-up spot with Brooks Koepka. "It was not easy with the wind, and you know, he kept calm. That's unbelievable and great stuff." Mickelson briefly lost the lead near the beginning of the last round. But Koepka, who went in front, took a dip, eventually going through a seven-hole stretch at four over. Mickelson needed to be sharp given the circumstances. "I love the challenge of competing against such great players," he said. "What an incredible competitor and tough player Brooks Koepka is, and to have a chance to play in the final group with him was an exceptional honour."