Playing in the championship for the 20th time, the burly 42-year-old Northern Irishman tamed the treacherous Royal St. George's links to protect his overnight lead.  

He could even afford two bogies at the finish as he tapped in at the 18th for a masterful final round 70 to win from playing partner Dustin Johnson and Phil Mickelson.  

Former Ryder Cup hero Clarke had not even made the top-10 at one of golf's four majors for 10 years and had arrived at Sandwich almost unnoticed amid the pre-tournament hype over young compatriot, US Open champion Rory McIlroy.  

Four vintage rounds later in some of the most testing condition seen at the Open, the cigar-loving Briton strolled off with the 900,000 pounds ($1,450,653.600)winner's cheque and a two million pounds bonus from sportswear giant Mike Ashley who supplied Clarke's kit without a regular fee but promised the mega-major bonus five years ago.  

Leading a major after three rounds for the first time in his 22-year professional career, Clarke calmed any early nerves by draining a long par putt at the first and despite a burst of brilliance shot-making from Phil Mickelson he never wavered.  

Maintaining the tee-to-green brilliance he showed on Saturday he was a model of calm as he played nerve-less golf down the stretch before taking the acclaim of massed ranks surrounding the 18th green.  

It had been that way all the way round.  

With thousands of fans heading supporting the 42-year-old he sank a long birdie putt at the par-four second — huge roars booming around the wind-blasted links course as his ball disappeared into the cup to give him a three-shot lead.  

After parring the third he dropped his first shot of the day at the fourth after an errant tee shot ended in the rough and he failed to hole a tricky putt for par.   With news of Mickelson's charge filtering through, Clarke had sniffs of birdies at five and six before he matched the American's earlier eagle at the seventh — holing a 25-footer to re-establish himself as the stand-alone leader at seven under as torrential rain began to fall.  

Two more pars took him to the turn in control and with the finish line in sight, albeit with some nerve-jangling tests still to come as the wind refused to abate.  

A birdie putt lipped out at the 10th and he then got up and down at the par-three 11th after his tee shot ha trickled into a steep greenside bunker.  

With Mickelson fading, Clarke's nearest rival was now playing partner Johnson who took picked up two shots after the turn to keep up the pressure.  

However, Johnson smashed his approach shot out of bounds on the brutish par-five 14th on the way to a double bogey seven to give Clarke a little more margin for error and when the big man speared his third shot to the heart of the green the famous old Claret Jug was his to lose.  

Clarke drove into trouble at the 15th but had a slice of luck when his second shot just missed a bunker and rolled up toward the front of the green.  

Not even a dropped shot at the 17th where an eight-foot par putt slid past to cut his lead over Johnson to two going down the last could disturb Clarke's composure.  

Johnson made a mess of his tee shot and when Clarke boomed his down the 18th fairway he could walk the 459-yards to the green soaking up the applause and could even smile when his par putt slid wide.