• Irishman’s third-round 63 is lowest score so far by two • Tommy Fleetwood four shots back in second after 66

Sometimes sporting outcomes give the impression of being written in the stars. Shane Lowry has enough to occupy his thoughts, without contemplation of becoming the latest symbol for a collective will in Ireland but, should he lift the Claret Jug at a venue deemed unsuitable for the Open Championship amid decades of civil unrest, golf will have delivered a last laugh towards bitterness. Sport’s unifying qualities are such a great strength; how they were endorsed as Lowry pulled Royal Portrush to pieces.

Lowry, who heads into the Open’s final day holding a four-shot lead, was cheered to the rafters on Saturday in a form which demonstrated just how much this Northern Irish crowd want the man from rural County Offaly to see the job through. Although always within boundaries of respect, the genteel sport of golf took on tribal form. A wide grin barely left Lowry’s face; and no wonder.

The only apparent danger to him is that many of this raucous contingent seemed to think his name is already on the Jug. Just 63 shots for Lowry on Saturday, 30 of them in the last nine, was the lowest score of this tournament by two. “Honestly, walking from the green to the next tee, the people are literally a yard away from you roaring in your face as loud as they can,” Lowry said. “If you have to get up and hit a drive down a tight fairway, it’s fairly difficult.”

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For so much of this third round, Lowry was embroiled in an almighty scrap with JB Holmes, Tommy Fleetwood and Lee Westwood. Holmes flatlined - though he still shot 69 - and Westwood played his back nine in two over par. Fleetwood did not do anything wrong at all; his 66 still left him four adrift of the imperious Lowry.

Three successive birdies from the 15th were sufficient to create an element of leeway for the 32-year-old which means he can perhaps only give this Open away. His glorious four-iron tee shot into the 16th made a mockery of the hole name - Calamity - and endorsed his level of confidence. That he has no major title to his name made that spirit all the more admirable.

Lowry needs no reminder that he also led by four with 18 to play in the US Open of 2016 at Oakmont; he duly slipped to a closing round of six over. “When I finished, I looked at the leaderboard, four ahead, I said to [his caddie] Bo [Martin] ‘At least I won’t have to answer any questions about Oakmont, I’m four ahead going into the final round of a major,’” said Lowry with a smile. “If I’m sitting here this time tomorrow evening [having won] it will be one of the biggest things that ever happened to me, there’s no denying that.

“But I felt at the time in Oakmont my golf just meant a lot more to me back then than it does now. I’m not saying that it doesn’t mean everything. It’s my career. But I’ve got certain things in my life that make it different. I’ve got family now. No matter what I shoot tomorrow my family will be waiting for me.”

Facebook Twitter Pinterest Shane Lowry walks on to the 18th green at Portrush. Photograph: BPI/REX/Shutterstock

Oakmont does not directly compare with Portrush because of weather disruption which ensured Lowry finished round three only on Sunday morning. The R&A have taken preventative action owing to extreme gusts and heavy rain forecast for Northern Ireland. Round four tee-times have been advanced by two hours.

Lowry’s current aggregate is 16 under. At minus 12, Fleetwood is two clear of Holmes. Justin Rose and Brooks Koepka - the last has endured all manner of frustrations on the greens - are now seven behind. It is a stretch to see anybody outside this group winning but Westwood and Rickie Fowler, who sit eight under, will not have given up hope.

Lowry admirably strayed from cliché when assessing how to approach inevitably the most nerve-racking moments of his career. Yet this is a golfer who has produced the extraordinary before; a decade ago, when still an amateur, he stunned the world of golf by winning the Irish Open. “Obviously I’ll go to bed thinking about holding the Claret Jug,” Lowry added. “It’s only natural, isn’t it? We’re human. We’re not robots.

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“There’s no point in saying I’ll go out and enjoy myself tomorrow because it’s going to be a very stressful and very difficult day. So I’m going to take the bad shots on the chin and I’m going to take the good shots and try to capitalise. I’m just going to be myself and play my game and see where it leaves me.”

Having started the day at seven under, Westwood reached double digits by the 5th tee. It feels harsh to criticise a Westwood round of 70 that keeps him in contention, aged 46, but the kind of trouble that ensued over the closing stretch was ominously familiar. Not so Fowler, who signed for a 66, his best round of the week by three.

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Rose had been treading water before an eagle at the 12th. He was 10-under after a birdie at the 15th but handed a shot back to the course after a miscued tee shot on the next. Holmes’s afternoon was afforded gloss by a fine birdie at the last. Thereafter, the American was fulsome in praise for Lowry, his playing partner. “I don’t know how many times in history you get the opportunity to witness that or be around that, to have somebody from the home country and put a round up like that in an Open, “Holmes said. “It’s pretty special, something I’ll never forget.”

Lowry is 18 holes from adding to a quite remarkable run of Irish major glory, kicked off in this very event by Padraig Harrington in 2007. Easy to say: if Lowry performs half as well as was the case on Saturday, it will be similarly straightforward to do.