Darren Clarke stared down challenges from Phil Mickelson and Dustin Johnson to win the British Open at Royal St George's on Sunday.

The Northern Irish-born 42-year-old carded an even-par 70 in wet and windy conditions to lift the claret jug ahead of the American duo, who finished three strokes behind on two-under overall.

The margin between them belies the contest, however, given Clarke was happy to take bogeys on his 71st and 72nd holes to ensure he would clinch his maiden Major.

Clarke, who came into the final round with a one-stroke lead over Johnson, sank a championship-winning eagle putt on the par-five seventh to leave him two under on the front nine.

He treaded water with par after par on the back nine until he reached the 17th tee, by which time Mickelson and Johnson had fallen out of contention at five strokes behind.

Four-time Major winner Mickelson seemed destined to add the claret jug to his trophy cabinet after eagling the seventh just moments before Clarke.

The left-hander, who had started the morning five strokes off the pace, then birdied the 10th to draw within a stroke of the leader.

But it all fell apart for Mickelson as he carded four bogeys in the next six holes, returning to the clubhouse with a 68 that was only good enough for second.

Johnson was still in contention until he sprayed his approach out-of-bounds on the 14th.

The 27-year-old took a drop and a double-bogey on his way to a 72.

Dane Thomas Bjorn (71) finished in outright fourth despite also threatening on the final day, while American trio Chad Campbell (69), Anthony Kim (70) and Rickie Fowler (72) shared a tie for fifth on even par.

Spain's Sergio Garcia equaled Mickelson for the lowest round of the day to rocket up the leaderboard into a tie for ninth at two over with Simon Dyson (70) and Davis Love III (72).

His compatriot Miguel Angel Jimenez did not fare so well, carding a dismal 78 including a triple-bogey to fall from fifth to 25th at seven over.