The British Open was a two-horse race when the final group stepped to the first tee Sunday afternoon, and Henrik Stenson and Phil Mickelson delivered a duel for the ages at Royal Troon. Stenson, with a major championship record round of 63, won his first career major, beating Mickelson by three strokes.

Stenson gave up his lead immediately with a two-shot swing at the first hole, carding a bogey while Mickelson drained a birdie putt. Stenson was nearly flawless afterward, carding 10 birdies - while Mickelson was putting together a phenomenal round of his own.

Henrik Stenson and Phil Mickelson's battle over the front nine. #TheOpenhttps://t.co/tJRfX0GFVw

— The Open (@TheOpen) July 17, 2016

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Mickelson would go on to shoot a 6-under 65 - the best round of the day other than Stenson's - but it wasn't enough. The 40-year-old from Sweden sealed the win with a 51-foot putt on the 15th hole that put him up by two with three to play.

He's holed it. Two shot lead for Stenson with three to play. #TheOpenhttps://t.co/xCrK3OtiXK

— The Open (@TheOpen) July 17, 2016

What a huge putt from @henrikstenson that was a beauty. Not over yet needs to finish this off. @TheOpen Claret Jug.

— Ian Poulter (@IanJamesPoulter) July 17, 2016

Boom 💪💪💪

— Shane Lowry (@ShaneLowryGolf) July 17, 2016

Wow, Henrik throwing his Vikingfist as he continues his birdiefest!#BritishOpen #LetsFinishItOff 👊💪

— Freddie Jacobson (@FreddieJac) July 17, 2016

Stenson capped his victory with a birdie putt at No. 18 that tied Jason Day's record for low cumulative score in major history, and Stenson's fellow competitors were blown away.