Phil Mickelson
American Phil Mickelson after sinking a birdie putt on the final hole of the Open Championship. Reuters

Shooting an incredible five-under par 66, American Phil Mickelson captured his first Open Championship with six birdies in the final round on Sunday at Muirfield.

It is the fifth major championship of the 43-year-old’s career, and redeems his second place finish at the Open in 2011, and his sixth runner-up showing at the U.S. Open last month.

Despite starting the round in ninth place, Mickelson finished with a three-under 281, and was the only player to shoot under par in the tournament thanks to four birdies on his final six holes.

With some of the best putts of his career, Mickelson sunk a short downhill shot on the 18th hole amidst roaring cheers from the crowd, and then had to wait for the rest of the field to finish to claim the Claret Jug.

England's Lee Westwood held the lead heading into Sunday, but eventually fell to a three-way tie for third with five bogeys on his way to a four-over 75.

Having never come back in a final round to win a major, Tiger Woods started the day tied for second, but dropped to fifth with six bogeys for a three-over 74, and finished with a two-over 286 in a tie for sixth place.

His tee-shot on the 16th fellow well short, but Mickelson’s found a way to save par and birdied the final two holes.

“I’m playing some of the best golf of my career,” Mickelson said to ESPN after the final round. “Today was one of the best rounds I’ve ever played, and it’s the best I’ve ever putted.

“I was seeing the line, it was just going in the hole. It was just an incredible day on the greens.