When he took his jersey off before sending the ball to within 15 feet of the pin at the 17th it appeared to be the only time Henrik Stenson appeared to feel the heat all day.

With commentators searching for phrases that would offer neat comparisons between this head-to-head clash of two Ryder Cup veterans and the legendary showdown between Tom Watson and Jack Nicklaus in 1977, both his playing partner and the Swede himself provided him with every opportunity to weaken, but as the pressure increased so he became ever more composed.

With the elements making a first abortive attempt to play their part in this latter day remake of the ‘Duel in the Sun’, he might have cracked as early as the opening hole when an under-hit approach perhaps betrayed some tension, leading as it did to an unlikely start to a record-setting round.

Mickelson had seized the initiative, giving his supporters the first opportunity to make their presence felt, by knocking his first approach in to tap-in range, yet Stenson set the tone for his afternoon by responding to his bogey with three successive birdies.

On the third hole it had meanwhile become evident that his support might have an added dimension in these parts since a chant, accompanied by several thumps on a refuse bin, seemed to come readily to the lips of spectator in a green baseball cap: “We believe… we believe Henrik.” Aware he was up against another favourite with many in these parts Stenson was appreciative of what backing he received.

“I've really felt the support here as well, even though Phil is a very popular major champion and a very popular player,” he said.

“There was a lot of encouragement for Phil but also for myself out there, so I really want to thank the fans for doing their part. They were really pushing me on.”

The quality of what those galleries witnessed was further illustrated by Stenson having lost the honour as they walked to the fifth tee, Mickelson responding to the third of his birdies by firing in a 10 foot eagle putt to draw level once more. Up against a contemporary who has won five majors in a period during which he had finished in the top five on no fewer than seven occasions that, too, might have tested his resolve.

Instead two more birdies at the sixth, matching one from Mickelson and the Postage Stamp eighth, saw him regain the lead and in between times there was a clue as to his state of mind at the seventh hole with a matchplay moment as, even before Mickelson’s off line drive had landed, Stenson pulled an iron from his bag. Both were acutely aware that the counting mechanism might be strokeplay, but this had become a match and must be treated as such.

“We managed to pull away from the rest of the field and we both played some great golf,” Stenson observed afterwards.

That they did and while the Scottish weather behaved itself for once by properly rewarding those who had played the week’s best golf, context was offered by the scores produced by the two men immediately in front of them as Andrew Johnston struggled home in 38 for a 73 that was still good enough to earn an eighth placed finish and Bill Haas, who was unable to register a birdie all afternoon in recording a four-over-par 75.

Mickelson would finish 11 shots clear of the next best in the field, JB Holmes, further even than Nicklaus had done at Turnberry 39 years earlier when Hubert Green had said of finishing third: ‘I won the tournament I was playing in.”

It was understandable, too, that Mickelson seemed flabbergasted at having shot 65 in the final round and finished three times as far behind the winner as he had started, not least because the difference was made on the stretch of holes the left-hander had identified as giving him an advantage over right-handed rivals in terms of the shape of shots required.

That had seemed unlikely when, Mickelson having followed his 10 foot birdie putt at the 10th by sinking a matching eight-footer, Stenson stumbled once more with a three putt from long range at the treacherous 11th for his second bogey of the day.

Mickelson had punched the air when he birdied the 10th, thinking it significant, but it was Stenson who was repeatedly doing the fist-pumping as one putt after another rattled in during an astonishing closing effort.

The 25-footer which put him ahead for the final time earned the first of them and the 60 footer from the fringe of the 15th could not have been more wounding, while the American spectator who shouted at his compatriot as he had walked down that fairway “You got this Phil… for America man, for America,” was evidently unaware of what tends to happen when Mickelson confronts Europeans on international duty.

It was, however, just before he removed his sweater on the 17th tee, as the sun made its second faltering effort to break through, that Stenson confronted what he considered his moment of truth, having dragged his second shot at the long hole into trouble, but recovered well.

“The putt on 16 was huge. Phil missed his eagle putt, so it looked like it was going to go in and I expect him to make every putt… you have to,” he said.

“It just snuck by and I'm standing over a five-footer down the hill. That was a very important putt to make.”

Stenson knew then that two more good swings, off the tees at the short 17th and the 18th would see him home, albeit the second of them was almost too good as he drove perilously close to the bunker a similarly adrenaline-fuelled Greg Norman had seen his Open bid end in 1989.

He finished with yet another birdie, just as Tom Watson had done all those years ago and if no-one has yet come up with a pithy phrase to encapsulate it, this was a sporting duel that those of us fortunate enough to have witnessed will never forget.