McDowell shot a final round 68 to finish the tournament at 13 under par, two shots clear of South African James Kingston (66), and earn himself the biggest cheque of his career - 500,000 pounds (one million dollars).

"This is just unbelievable, it really was a tough weekend's golf and it is a massive relief," McDowell said. "I have never had a two-shot lead coming up the last in a professional tournament and I have to say I prefer it to the play-offs.

"I don't think I've ever shaken as much as I did coming done that stretch."

It was a particularly emotional day for the Northern Irishman with his recently-retired father, mother and a host of other relatives in the huge galleries.

"My dad first put a club in my hand when I was seven and he's been with me for 20 years, through thick and thin," he said. "He just retired last Friday. This is my retirement present to him. He's an emotional man and I'm sure there'll be a few tears tonight."

Only extraordinary bad luck can now deprive McDowell of a place in the European team that will take on the Americans in Kentucky in September.

"I put the Ryder Cup up there with winning majors," he added. "It's something I have really, really desperately wanted.

"I refused to be measured for my Ryder Cup clothes last week but maybe I will accept next time. It's never over till it's over of course but this is a massive step in the right direction. It will be a dream come true."

Australian left-hander Richard Green (69) and Spain's Miguel Angel Jimenez (69) tied for third place a shot further back while Englishman Simon Khan, who had shared the overnight lead with McDowell, slipped to fifth place after a disappointing final round of 72.

Khan had the consolation of booking the last available place in next week's British Open at Royal Birkdale, a slot he only secured by getting up and down from the greenside rough on the 18th hole.

The Englishman had walked off the 11th green two shots clear of McDowell after claiming a birdie to the Northern Irishman's bogey.

But he immediately handed back his advantage with a double bogey six on the 12th and the momentum shifted decisively in McDowell's favour when he struck a superb approach to the 15th green that finished within three feet of the pin.

McDowell holed the putt for birdie while Khan's wild drive resulted in a bogey and the Englishman's challenged died with another double bogey on the short 17th.

"It is great to be in the Open," Khan said. "But at the moment it feels pretty disappointing because I gave myself a lot of chances today."

Green was left with a similar sense of having missed an opportunity to claim one of the biggest prizes in European golf.

"I'm a little bit disappointed that I did not make another couple of birdies and contend," he admitted. "It was unfortunate the putts did not go in again but all in all it has been a good week.

"I feel I am playing as good as I've played the game throughout my career and hopefully it will stick around for next week."

There were no regrets for Kingston, who surged up the field after only just making it to the weekend.

"That's probably as close to flawless golf as I have played," said the 42-year-old. "It felt like I hit almost every fairway.

"I really could not do much more. I had a great weekend to go from just making the cut to being in contention."

None of the big guns in the field ever looked like firing on the final day.

World number two Phil Mickelson could only manage a closing 73 to finish well down the field on two under.

Ernie Els finished with a 69 that left him in a share of ninth place and positive about his form as he heads for Royal Birkdale.