PORTRUSH, Northern Ireland — With foul weather forecast for Sunday at Royal Portrush, the day to make birdies in the sunshine was Saturday at the British Open.
The leaders took the hint in the third round, generating more roars than respectful silence as they navigated the green and undulating course in relatively calm and benign conditions.
No man got more support than Shane Lowry, a stocky and bearded Irishman whose father, Brendan, was a prominent Gaelic football player.
The son is quite a golfer, and at age 32 after a brilliant round of 63 on Saturday, Lowry now has the opportunity of a lifetime: a chance to win the first Open championship on the island of Ireland since 1951.
“There’s no point in shying away from it,” he said after heading into the third round with a share of the lead. “I’m in a great position, but, my God, have we got a long way to go.”
Not quite so far anymore. He is now at 16 under par with a four-stroke lead over the Englishman Tommy Fleetwood. But Lowry still must navigate one more round under a major spotlight even if the heavy rain in the forecast may make it difficult to see anyone clearly at Portrush with the claret jug at stake.
Lowry has yet to win a major championship, but he has been in this position before. In the 2016 United States Open at Oakmont Country Club, he also had a four-stroke lead heading into the final round, only to shoot a six-over-par 76 on Sunday.
He finished tied for second behind the winner, Dustin Johnson, which would have been cause for celebration under different circumstances.
This time, Lowry will have the crowd behind him as the only man from Ireland or Northern Ireland in contention. But he has some serious challengers: Fleetwood, one of the stars of Europe’s Ryder Cup victory over the United States last year, is at 12 under. J. B. Holmes is at 10 under.
Brooks Koepka, ranked No. 1 in the world, is at nine under after finishing his round of 67 on Saturday with consecutive birdies. Koepka has been the most consistent player in the majors this year: He tied for second at the Masters, won the P.G.A. Championship and finished second again at the U.S. Open.
But he is a long way — seven strokes — behind Lowry, as is the former U.S. Open champion Justin Rose.
Holmes and Lowry started the third round tied for the lead at eight under par. With their similar builds, peaked caps and full beards, it was sometimes difficult to tell them apart.
The writer Rick Reilly joked that they were “the same guy separated by an accent.”
But their golfing fortunes diverged on the back nine as Lowry continued to find greens and hole clutch putts. He finished with eight birdies and not a single bogey, setting a course record on the newly reconfigured Royal Portrush links.
He came within about an inch of shooting 62. His 25-foot birdie putt on the 18th stopped on the left edge of the cup. But his walk up to the 18th hole on Saturday was still a moment to savor.
After Lowry hit his approach shot onto the 18th green, he made the long walk with the gallery serenading him. He doffed his cap, looking left and right at the packed grandstands.
This is the first Open championship to be held at Royal Portrush since 1951; the biggest golf event to be held on the island of Ireland since the Ryder Cup in 2006.
But Saturday could well have been the calm before the storm, with rain and high winds of 30 to 40 miles per hour expected on Sunday afternoon.
“You’ve just got to take what you get,” said Rickie Fowler, the American who is at eight under par along with the English veteran Lee Westwood. “That’s links golf. That’s the Open. There’s nothing you can do about it. Go throw the waterproofs on and have fun.”
Open organizers moved up the tee times on Sunday to avoid the worst of the weather, but the pressure will be there for Lowry no matter what.