JORDAN Spieth has won the British Open after denying fellow American Matt Kuchar in a dramatic final-round duel at Royal Birkdale.

Spieth’s extraordinary one-under-par 69 on Sunday — featuring three back-nine birdies and an eagle after he’d relinquished his three-shot overnight lead — earned the 23-year-old a tension-filled three-stroke victory at 12-under 268.

Little-known Haotong Li, at six under after a blazing Sunday 63, was outright third at six-under 274, with former champion Rory McIlroy (67) sharing fourth with Rafael Cabrera Bello (68) a further stroke behind.

Australian Marc Leishman finished in a five-way tie for sixth at four under after closing with a stylish 65.

But the day — and the famous Claret Jug — belongs to Spieth. In adding the Open crown to his 2015 Masters and US Open triumphs, the world No.3 joins the legendary Jack Nicklaus as only the second player to have won three of golf’s four majors before the age of 24.

“This was eventful. Seventeen pars and a birdie would have been fine too, but there are a lot of roads to get there,” Spieth said

Jordan Spieth of the United States, right, is congratulated by Matt Kuchar after winning the British Open. Source: AP

Turning 24 on Thursday, Spieth will head to next month’s US PGA Championship at Quail Hollow striving to become only the sixth player after Tiger Woods, Nicklaus, Gary Player, Gene Sarazen and Ben Hogan to complete a career slam. He would be the youngest to achieve the fabled feat - and few will back against him after Sunday’s remarkable display of defiance.

After dropping three shots during a nervy front nine as Kuchar drew level, worse was to come for Spieth.

A wildly errant tee shot on the 13th evoked memories of last year’s Masters meltdown when Spieth threw away the green jacket with a disastrous quadruple seven around Augusta National’s Amen Corner.

Spieth sliced his tee shot almost 50 metres right, over a tall sand dune near the driving range.

After a lengthy deliberation and consultation with officials, the Australian Open champion ended up taking an unplayable lie and hit his next shot from the driving range - and near a Titleist truck.

The bizarre sequence played out in slow motion as Spieth took more than 20 minutes before hitting his shot.

Marc Leishman finished best of the Australians. Source: Getty Images

His blind three iron cleared the dune and ended up in front of a bunker short of the green.

Spieth then pitched up and made a clutch two-metre putt for a bogey that will go down in Open folklore.

Kuchar made par to assume a one-shot lead, but what followed was nothing short of astonishing.

Spieth almost aced the par-3 14th, then made eagle on the par-5 15th and further birdies on 16 and 17 to leave his playing partner and Ryder Cup teammate shell- shocked after a wild three-shot swing.

“I was in a tough one early on, but I showed resilience. As you can imagine thoughts came in from my last scenario where I was leading a major on a Sunday,” Spieth added.

“The wheels had kind of come off everything and we were trying to work out how to get back on track to salvage the round, and it took a bogey to do so.”

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