Mickelson Stenson. It sounds like a Glasgow accountancy firm. And down the road on the Ayrshire coast the numbers certainly added up for an experienced pair who know a thing or two about taking pair of business in the Open Championship.

As the sun rose early on Thursday morning, and rise it did on that dreamy opening day which already feels so long ago, 156 men awoke with designs on the Claret Jug.

By the time the final pairing had reached the turn on Saturday, the destiny of the 145th Open Championship was pretty much in the hands of the Mickelson Stenson partnership alone.

We should not be surprised – this is a duo with real Open pedigree.

Mickelson, the champion at Muirfield in 2013, which remains his most recent win of any description, and the owner altogether of five Major titles, first played in the Open as long ago as 1991.

day three of The OpenStenson may never have won the Claret Jug, or any Major for that matter, but he has an impressive back catalogue of results in this event. The Ryder Cup star was third at Birkdale in 2008 and again at St Andrews two years later, not to mention being runner-up behind Mickelson at the home of the Honourable Company of Edinburgh Golfers.

It isn’t easy to be the front-runner in a Major but here it was the chasing pack who looked under the greater pressure.

There are relatively few halfway leaders who inspire any great confidence that they are likely to finish the job off. You would have to say that Messrs Mickelson and Stenson are two of them.

Mickelson Stenson Troon Saturday

As a pair, Mickelson Stenson presented a formidable front. Perhaps in the future, when the USA and Europe are required to combine to take on the might of the new golfing superpower China, these two could be wheeled out of retirement to play in the opening fourballs.

It probably also helped them to keep moving forward on a day when virtually all their most likely challengers gradually fell away.

There was to be no charge from Johnson (of either the Dustin or Zach persuasion), Day, McIlroy, Garcia, Kaymer or Kuchar.

In their absence, it was effectively the spark of matchplay that kept them both moving forward. You wonder how either would have reacted had they been playing with, say, Soren Kjeldsen or Kaymer, to name but two, as they struggled to scores in the mid-70s.

Might they have become defensive, content to throw in the occasional bogey?

We will never know.

McIlroy Troon Saturday

Mickelson Stenson

In this world of Mickelson Stenson, and there will be a further, decisive instalment on Sunday, barely a backward step was taken.

Let us be clear – it was the currently Major-less Swede who owned the long game, his ball-striking for a second-day running nothing less than imperious.

Rich Beem, the 2002 PGA champion, described the sound his iron shots make as “the kind of thing you only get with one or two players in a generation”.

The quartet of long irons that was dispatched into the heart of the 13th, 14th, 15th and 17th greens showed Stenson at his absolute best. Each was followed by that look of faint disgust on his face, dismissing the ball from his view in the certain knowledge it would next be seen obediently next to the flag.

Mickelson’s long game was not in the same league – frankly, whose would be? – but he played with great craft, like a man who knows what the secret is to prevailing on a championship links. His short game was simply brilliant.

The striking with his wedges was as precise from a clump of wet Scottish clag on the 6th as when confronted with a tight lie in front of a bunker on the 11th when lesser mortals would have been mindful of the Stranraer to Glasgow railway line that runs beyond the green.

Between them, they ran up just three bogeys – and this on a day when McIlroy and Day carded four each, Dustin Johnson one and a treble (inevitably at the 11th), Garcia four and a double and Zach Johnson two doubles.

Which man will prevail?

On Sunday, perhaps some daylight will emerge between them.

Based on the evidence of 54 holes, over which period they have been playing a different game to the rest of the field, it looked like they were simultaneously trying to claim the same prize at an awards ceremony.

A bit like one of those awkward conversations when both parties start speaking at the same time, eventually one of the two will have to stand aside.

Mickelson Stenson or Stenson Mickelson? A repeat of Muirfield three years ago or revenge for the Swede?

It really isn’t clear yet, but it feels as though the other 154 competitors are going to be no more than bystanders.