Phil Mickelson wins The Open Championship 2013

Phil Mickelson, 43, won the British Open at Muirfield on Sunday with a superb final round 66.

He was five strokes behind leader Lee Westwood entering the final round. At the end of it all, he had won with three strokes to spare, ahead of Sweden’s Henrik Stenson. Westwood and Ian Poulter were a further shot behind.

“I never knew if I would be able to win this tournament,” Mickelson admitted later while he was waiting to collect the claret jug. “I always hoped and believed, but I never knew it — until about an hour ago.”

“This is such an accomplishment because I never knew whether I’d be able to develop my game to play links golf,” he added.

“I played arguably the best round of my career, and shot the round of my life. It’s such a difficult six-hole finish, I putted so good. It feels amazing. The range of emotions I feel are as far apart as possible after losing the US Open. But you have to be resilient in this game. These last couple of weeks, these last couple of months, I’ve played some of the best golf of my career.”

Mickelson was in his 20th Open campaign and this was his fifth major title after asters in 2004, 2006 and 2010 and the US PGA in 2005. He becomes the third consecutive player in his 40s to win the Open, after Ernie Els and Darren Clarke.

He has also become the first player ever to win the Scottish Open and British Open in consecutive weeks.

“He’s stronger than he’s ever been,” said Mackay, Mickelson’s caddie who has been with the American all the years in a 21-year pro career. “He’s fitter than he’s ever been. He’s hungrier than he’s ever been. You can’t [overstate] how much he wants to compete and do well.”

Tiger Woods started the day two shots behind Westwood, but carded a poor 74 to finish tied sixth overall, five strokes behind Mickelson.