Gutsy McIlroy, 25, became the first UK player to win back-to-back majors.

Holywood golf club general manager Paul Gray said: “It is legendary stuff.”

Club professional Stephen Crooks has lauded him as a once-in-a-generation player and predicted he could go on to win eight majors.

There was a joyful atmosphere on the manicured fairways in hills overlooking Belfast where it all began for McIlroy – who dreamed of winning golf’s most glittering prizes from age two or three and used a plastic club.

He said it had been a summer beyond his wildest dreams.

Mr Gray said he deserved to take his place alongside the likes of Arnold Palmer and other greats of the game to have won back-to-back majors after the thrilling finale in Kentucky.

“It was great that he won again, unbelievable. I cannot believe he actually won that. To see someone who has grown up here on our own course do well is fantastic. To do what Rory has done is hard to believe, at times you have to pinch yourself.”

The world number one has said golf is his life after his break-up with tennis player Caroline Wozniacki. He won the Open in July and his rich seam of form continued with another important victory in a recent tournament in Ohio.

Mr Crooks has said the country may not see another golfer of the calibre of the precocious schoolboy who rose to the very top. He has spent the last 14 years at the club and remembers when McIlroy was a 12-year-old boy whose only aim was to get on the greens with his clubs.

McIlroy has become the third youngest player of the modern era – after Tiger Woods and Jack Nicklaus – to win four of golf’s biggest prizes, while he also becomes the first man to win back-to-back majors since Ireland’s Padraig Harrington in 2008.

Among his next goals will be the US Masters, the last piece of the four-major Grand Slam.

The all-conquering athlete can expect a windfall through endorsements linked to his growing status. The prize for winning the PGA is worth £1.1m.

While the exact figures have not been made public, it has been reported that his contract with Nike will earn him up to $250m over 10 years.

There have been predictions he could dominate the game for the next 15 years.

Stormont First Minister Peter Robinson and Deputy First Minister Martin McGuinness said his run of form had been stunning.

They added: “He is a sporting sensation and joins an impressive list of champions to win back-to-back Majors.

“We are incredibly proud to watch as he writes his story of golfing greatness and we look forward to the next chapter as these victories propel him towards being the golfer of his generation.”