A quick squint through the news pages ahead of the third round of the 145th Open Championship here at a bracing Royal Troon revealed an intriguing development. The intrepid old adventurer Sir Ranulph Fiennes announced he would be embarking on yet another death-defying challenge and those in the media centre gazing at Colin Montgomerie slithering down to last place on the leaderboard immediately thought "crikey, he’s going to try to ask Monty for a quote?"

This tenuous theme of frosty receptions and polar explorations was somewhat apt, of course. It was a particularly parky day on the vigorous Ayrshire coast and the sight of Henrik Stenson taking to the driving range in a woolly hat and mittens simply illustrated the general scene. “See you on the slopes,” said the Swede ahead of his third round shoot-out with Phil Mickelson. Moving day? You had to get going just to keep the circulation birling. By the end of it, Stenson had manoeuvred his way to the head of the standings after a fascinating, fluctuating fight with Mickelson. His three-under 68 for a 12-under 201 left him one ahead of the man who thwarted his bid for a maiden major in the Open at Muirfield in 2013. The duo are set for another captivating Sunday showdown. “There’s always revenge,” said Stenson with a smile.

Yesterday was not so much the Duel in the Sun, which happened down the road at Turnberry almost 40 years ago, but more the clash under the cloud cover. Well ahead of the rest – American Bill Haas is six off the lead – Stenson and Mickelson were embroiled in their own private tussle which developed into a kind of Ryder Cup-style nip-and-tuck matchplay encounter. This was a display of terrific, controlled golfing competition in testing conditions. Mickelson, aiming to become the oldest Open winner since 1867; Stenson striving to become the first Scandinavian male golfer to win a Major championship. Either way, history could be made today.

It was a tough, trying old Saturday and one for keeping the head when it would have been easy to lose it. Rory McIlroy certainly did. A frustrating two-over 73, which left him lagging 12 shots off the lead, reached its tipping point on the 16th when he hoiked a wild 3-wood approach, sent the offending club thudding off the turf and had to pick up the pieces as the head snapped off.

Wary of the hours of play they lost due to high winds at St Andrews last year, which ultimately led to a Monday finish, the Royal & Ancient officials decided not to cut or roll the greens ahead of the third round yesterday with boisterous gusts anticipated. The putting surfaces were rolling at 9.5 on the stimp, which was about as slow as Jason Day’s pre-shot routine. A couple of tees were also moved up while the treacherous Postage Stamp eighth was playing just 100 yards. With that menacing wind, it caused huge indecision for those trying to tackle its abundant perils. Length is not everything in this crash, bang, wallop era.

One behind Mickelson heading into the third round, Stenson served notice of his intentions with a birdie putt of 15-feet at the first to swiftly draw himself level before inching ahead with another birdie on the fourth. It was a brief stint in the outright lead. Following a leaked shot on the sixth, the pesky Postage Stamp left Stenson in a muddle and a trip into the bunker dropped him a stroke behind again. A par-putt of some 35 feet on the 10th was crucial for Stenson – “that was a key moment to stay in the ballgame” - and it was on Troon’s rigorous, exacting back-nine where the cut-and-thrust really got going. After a great par save on 12 – his drive came to rest just in front of a gorse bush - Mickelson’s raking birdie putt on the 13th produced the first significant fist pump of the day. Yet, out of nowhere, there was a two shot swing on 14 as Stenson birdied and Mickelson, surprisingly, missed a short one for par. The trading of blows continued and Mickelson was up again with a birdie on 16. But Stenson responded as the pendulous nature of proceedings continued. A superbly flighted tee-shot into the par-3 17th spawned a birdie and he got his nose in front again as his rival failed to get up and down having missed the green on the left.

It could have been even better for Stenson on 18. Mickelson, distracted by a clicking camera, flung his approach into the sand but conjured a fine salvage operation to make his par in a 70 and finish just a shot behind. It had been a captivating contest which effectively put everybody else in the shade.

Well, everybody apart from Andrew Johnston, the burly, bearded, larger than life Englishman who won the Scottish Hydro Challenge on the second-tier Challenge Tour up in Aviemore in 2014 and is now leading the British challenge here at Troon after a 70 left him in a share of fourth on 208. Johnston's down-to-earth, happy go luck approach continues to capture the imagination and he merrily high-fived his way down the 18th fairway with a beaming smile as wide as the Firth of Clyde.

Rather like his bountiful facial hair, Johnston’s cult following just grows and grows.