The legend grows, and where better to perform further heroics than on your home patch?

This was more than ticking a box, more than adding another title to his curriculum vitae.

In claiming the Dubai Duty Free Irish Open, Rory McIlroy – acclaimed by galleries who had defied one disruptive weather front after another throughout the tournament – added yet more lore to his prodigy.

For, let’s admit it, the man is a golfing genius.

And that McIlroy was required to show fortitude – his three-stroke lead at the start of the final round fall into negative equity when Russell Knox birdied the 14th hole for the Scot to move one clear – made this latest career win all the more impressive.

This was pure theatre, box office entertainment – only for real!

First tee

Having completed three holes from a disrupted third round that carried over from Saturday, McIlroy returned to a hotel where he watched highlights of Manchester United’s FA Cup win. By the time he marched to the first tee shortly before 11am for the final round, it was with a sense of destiny. Would he grab it?

The story became ever more entertaining and almost surreal as slowly Knox reeled him in.

An outrageous downpour – which brought hailstones that lined the fairways and greens – caused a suspension of play when the final group of McIlroy, Knox and Masters champion Danny Willett were on the ninth fairway.

On that front nine Knox, not Willett, had proven most up to the pursuit of McIlroy.

On the par-five fourth hole, the Scot – using a driver borrowed from his fellow PGA Tour player David Lingmerth after his own had cracked in Thursday's opening round – had split the fairway off the tee and hit a wonderful approach. He rolled in the eagle putt there, and followed with a birdie on the fifth. It was very much a case of game on.

Indeed, Knox had closed the deficit to just one stroke when the heavens opened and the hailstones came down with a ferocity that led to a suspension in play that last one hour and nine minutes.

As McIlroy made his escape from the ninth fairway, Knox whipped a camera from his bag and got his caddie to take a photo of him with giant hailstones all around him.

On the resumption it was back to business for Knox.

Up ahead Bradley Dredge was making inroads of his own but it was Knox – in McIlroy’s line of sight – who became the other player in a golfing duel that developed into one of intrigue and drama.

Few players perform drama as well as McIlroy.

On the 11th his putter betrayed frailty when he missed a short putt.

That bogey for McIlroy provided further incentive to Knox, who claimed back-to-back birdies on the 14th and the 15th (statistically the toughest hole on the course playing to 4.24) to move from one behind to one ahead of the tournament host.

As a teenager,McIlroy had stood and watched with other spectators by the signature 16th hole as Darren Clarke had his moment of joy in the 2006 Ryder Cup when sinking the winning putt in Europe's victory.

On this May day, with its many twists and turns, McIlroy claimed his own with a wonder shot to the island green in the river Liffey that Knox later acknowledged as “the turning point”.

“I had it in the back of my mind that my length might be an advantage,” said McIlroy, who nevertheless had never intended going for the green in two on the 16th. Not playing off the back tee.

But a monster drive changed his mind. With 238 yards to the front and 273 yards to the flag, McIlroy figured a “perfect” three-wood approach was on.

Risk-and-reward

McIlroy took on the risk-and-reward shot, his ball flying across the river to land on the green.

“One of those shots (where) you pick your target, you make a good, full, committed swing at it,” he explained with all the matter-of-factness of someone who responds best when pressure is applied.

McIlroy two-putted for eagle, and Knox , who had found a fairway bunker, suffered a bogey six. A two-shot swing and McIlroy had regained control.

If that approach shot on 16th provided the turning point, McIlroy's finish provided the pièce de résistance. Although his drive was pulled slightly left, it remained on the fairway.

In Wednesday’s pro-am McIlroy had found himself in almost the exact same position and hit a four-iron before throwing down another ball and hitting a five-wood. That practice shot proved hugely beneficial.

So it was that the five-wood was passed to him by caddie JP Fitzgerald for the approach shot. There was never any thought of playing a safe lay-up.

“I had a good yardage,” he said later: 222 yards to the front of the green, 256 yards to the flag.

His approach, magnificently executed, finished a couple of feet from the cup and in that moment everyone knew the game was up. Willett was the first to offer congratulate still on the 18th fairway.

When McIlroy rolled in the eagle putt – to sign for closing 69 for 276, three shots clear of Dredge and Knox – it was the final touch to an wonderfully crafted win.