Clarke is the first Northern Irish winner of the Open since Fred Daly in 1947
Darren Clarke kept his nerve to clinch his maiden major title with a three-shot victory in the Open at Royal St George's, reports the BBC.
The 42-year-old Northern Irishman fired a final-round 70 to finish five under to hold off Americans Phil Mickelson (68) and Dustin Johnson (72).
Denmark's Thomas Bjorn ended on one under after a 71 with American trio Rickie Fowler (72), Chad Campbell (69) and Anthony Kim (70) on level par.
Clarke, playing in his 20th Open Championship, is the first winner from the UK since Paul Lawrie in 1999 and becomes only the second Northern Irishman to win the Open after Fred Daly in 1947.
And he follows in the footsteps of countrymen Rory McIlroy and Graeme McDowell who both won their first majors at the US Open this year and last, respectively.
Clarke led by one from Johnson going into the last round and he showed complete control of his emotions as he smiled his way to the Claret Jug.
On a day of sunny periods and fierce squalls, Clarke picked up a shot at the second, handed it back at the fourth, and then eagled the long seventh to reach the turn at seven under for a two-shot lead over Mickelson.
Four-time major champion Mickelson had started the day five strokes off the lead and scorched around the front nine in 30, including his own eagle at the long seventh.
The 41-year-old left-hander picked up another shot at the 10th to close the gap to one, but his wheels fell off in spectacular fashion as he dropped four shots in six holes to end his chance of a maiden Open title. He did, though, beat his previous best Open finish of third at Royal Troon in 2004.
Johnson, 27, had scrapped hard to get to five under, just two behind playing partner Clarke after 13 holes, but went out of bounds on the long 14th and took a double bogey to hand the Northern Irishman a four-shot lead.
Thoughts turned to Bjorn, who had squandered a three-shot lead with four left at the same venue in 2003. But despite a bogey on the 17th, Clarke remained firm and none of his rivals could close the gap over the final few holes.
Walking down the 18th, the popular Clarke, who lost wife Heather to breast cancer in 2006, removed his visor and greeted the cheering crowd with the Claret Jug virtually secured.
A bogey was enough for the man from Dungannon as he hugged his mother and father and new fiancée Alison as the 2011 Open champion.
"It is just incredible. I'm a bit speechless. I played ok today, I did what I had to do and the last few holes when I was far ahead I just tried to be careful and not do anything stupid," he told BBC Sport.
"I've been very calm all week, I won six weeks ago and the more you put yourself in winning positions the more comfortable you get. I was very comfortable with my game this week.
"I could hear the roars going up for Phil Mickelson on the way round but I was hitting some shots and doing ok. Professional golf has its ebbs and flows, that's the way it goes.
"It's very special for me and the kids. They were playing at Portrush today and they will be very proud.
"The celebrations could be long and - not arduous - very enjoyable tonight."