Phil Mickelson birdied four of the last six holes to record a sensational final-round 66, and win the 2013 Open Championship by three shots on three-under-par.
The 43-year-old American followed up last week's Scottish Open play-off victory at Castle Stuart by claiming his fifth major, and first Open Championship title, after carding five-under-par on a dramatic last day at Muirfield.
Sweden's Henrik Stenson finished runner-up on level par - his highest ever placing in a major tournament - after a final round of 70, with English duo Lee Westwood and Ian Poulter a further shot behind, alongside Australian Adam Scott.
Westwood actually went into the final day with a two-shot lead, and extended that to three after a birdie on the fifth. However, he lost momentum, particularly down the last nine holes, to card a four-over par 75.
Poulter put himself in contention after an amazing run of eagle-birdie-birdie-birdie, before playing the last five holes in one-over-par to finish on four-under 67.
Masters champion Scott - who blew a four-shot advantage to finish runner-up to Ernie Els at Royal Lytham in 2012 - suffered a similarly torrid time in the closing stages this year, hit the front at one stage on Sunday, but faltered to finish with a disappointing 72.
Meanwhile, Tiger Woods's hopes of landing a 15th major title - and first since 2008 - were quickly shattered, after three bogeys through the first six holes. He eventually finished joint sixth on two-over-par, alongside Japanese youngster Hideki Matsuyama and opening round leader Zach Johnson.
Mickelson's Open record had been realtively modest until now, despite finishing third at Troon in 2004, and second at Royal St George in 2011.
But, after a stunning display this weekend, the left-hander has successfully completed the third leg of a career Grand Slam of all four majors, and makes up for his second-place finish behind Justin Rose at the US Open last month.
Mickelson also joins an illustrious list of former Muirfield champions, including Gary Player, Jack Nicklaus, Lee Trevino, Tom Watson, Nick Faldo, and defending champion Els, after victory in the third major of the 2013 season.