(CNN) -- It was wet, cold and windy, and he hadn't been in contention to win golf's oldest tournament for 10 years, but Darren Clarke finally made the breakthrough at the British Open on Sunday.
Two decades after he first entered the season's third major event, the 42-year-old made history as he triumphed by three shots from Americans Phil Mickelson and Dustin Johnson in its 140th staging at Royal St. George's in England.
Clarke, whose previous best finish was runner-up in 1997, lifted the coveted Claret Jug at his 21st attempt -- breaking the record of the tournament's previous longest wait, the 15-try streak that Zimbabwean Nick Price snapped in 1994.
He is the oldest British Open winner since Roberto de Vicenzo's 1967 victory aged 44, and the oldest of any major champion since 43-year-old Ben Crenshaw won the 1995 Masters.
"It's been a long and bumpy road, I have had some good things happen to me and some bad things, but I've had so much support from an awful lot of people," Clarke said at the prize-giving ceremony.
"I'd like to thank my parents and my fiancee Alison, and there's someone up there watching as well. To everybody, thank you very much."
Clarke became the third player from Northern Ireland to win a major title in the past 13 months, following Rory McIlroy's U.S. Open triumph last month and Graeme McDowell's success at the same tournament last year.
He is the first from his country to win the British Open since Fred Daly in 1947.
Clarke's agent Chubby Chandler now has three current major champions in his stable, with South African Charl Schwartzel winning the Masters in April before McIlroy's eight-shot triumph at Congressional.
Clarke has twice won World Golf Championship events, in 2003 and 2003, while he has finished second on the European Tour's money list three times.
He famously helped Europe win the Ryder Cup against the U.S. in 2006 -- his fifth appearance in the prestigious teams event -- a month after his wife Heather died from cancer.
Clarke dedicated his victory to his sons Tyrone and Conor, who were back in Northern Ireland where the family has returned after years living in London.
"It's for the kids. They played Royal Portrush (golf course) this morning and were watching on TV," he said.
Clarke, who last finished in the top-10 when he placed third at Royal Lytham & St. Anne's in 2001, could afford to bogey the final two holes as he carded a level-par 70.
It was his worst score in four rounds at the links course, which has been buffeted by the weather this week, as he took home the $1.45 million first prize to the cheers of the crowd in Sandwich.
Having started the final day one shot ahead of 27-year-old Johnson, Clarke faced a strong challenge from fellow 40-something Mickelson.
The left-hander, seeking to add the British Open to his three Masters and one U.S. PGA Championship crown, carded three birdies and an eagle to grab a share of the lead.
But Clarke restored his advantage as he also picked up two shots at the par-five seventh and then rattled off nine successive pars despite the difficult conditions, while his main rivals faltered.
Mickelson's challenge fell apart at the 11th hole, where he missed a routine short par putt. More bogeys followed at 13, 15 and 16 as he finished with a 68 to be two-under 278 for the tournament.
Johnson, seeking his first major title, drove out of bounds at the 14th and his double-bogey there handed Clarke a four-shot buffer. He also dropped a shot at 18 to fall back level with Mickelson.
First-round leader Thomas Bjorn, whose father died in May, finished fourth on 279 after the 40-year-old Dane closed with 71.
He was followed by three Americans -- Rickie Fowler (72), Anthony Kim (70) and Chad Campbell (69) -- who were tied for fifth on 280.
France's Raphael Jacquelin was eighth on 281, while Spain's Sergio Garcia, Englishman Simon Dyson and U.S. Ryder Cup captain Davis Love tied for ninth on 282.
Five-time champion Tom Watson tied for 22nd after a closing with 72, while McIlroy was equal 25th after a 73.
England's Tom Lewis was the top amateur, with the 20-year-old tied for 30th as he fell away after sharing the early lead with Bjorn following his opening 65.
Defending champion Louis Oosthuizen of South Africa was tied for 54th on 293 after ending with a 77.