Shane Lowry produced the finish of dreams in round three of the Open Championship to take a four-shot lead over Tommy Fleetwood heading into Sunday.

The Irishman brilliantly made the most of the favourable scoring conditions at Royal Portrush on Saturday to sign for an 8-under 63, just one stroke off levelling the lowest score in Open history, leaving him at 16 under for the tournament.

It would take a huge turnaround for Lowry not to make his major breakthrough on the Dunluce Links. After Fleetwood, Lowry’s nearest challengers are J.B. Holmes (-10), Brooks Koepka and Justin Rose (both -9).

But the threat of heavy rain looms large in Portrush, so there may yet be one final twist in this Open tale in Northern Ireland.

Below we profile the leading contenders and the best of the rest heading in round four.

THE MAIN CONTENDERS

SHANE LOWRY:

Age: 32

Best major finish: T2 at 2016 U.S. Open

Current ranking/highest ranking: 33/17

European/PGA Tour wins: 4

Reasons he’ll win: There has been a vociferous backing for Irishman Lowry this week at Portrush and it is an energy he has fed off to the greatest effect. He is also a dab hand on the links and has looked utterly unflappable this week.

Reasons he won’t win: There is a target on Lowry’s back and the last time he was in a scenario like this at the 2016 U.S. Open he did not exactly enjoy the pressure. Leading by four heading into the final round at Oakmont, he limped to a six-over-par 76 and finished three off winner Dustin Johnson.

TOMMY FLEETWOOD:

Age: 28

Best major finish: 2nd at 2018 U.S. Open

Current ranking/highest ranking: 20/9

European/PGA Tour wins: 4

Reasons he’ll win: Growing up in Southport, close to Royal Birkdale, Fleetwood just loves these type of golf courses and the adverse weather forecast for Sunday is unlikely to cause him too much concern. Seeing his good pal Francesco Molinari win this same tournament a year ago will also act as motivation to reel in Lowry.

Reasons he won’t win: The gap to Lowry is now a big one and he will need his last-day rival to lose the tournament as much as he will need to win it. All Fleetwood can do is make sure he is clinical when the birdie chances present themselves.

BEST OF THE REST:

J.B. Holmes

Reasons he’ll win: If either of the two men above him flounder, Holmes has shown throughout the weekend he can really play around Portrush. Three years ago at Troon he was the best of the rest as Henrik Stenson and Phil Mickelson played out one of the greatest final days in major history.

Reasons he won’t win: On a day where scoring was favourable, Holmes could only muster a two-under 69. If the bad weather arrives on Sunday, which it is fully expected to, chances to go low will be scarce.

Brooks Koepka:

Reasons he’ll win: Because that is what Brooks Koepka likes to do in majors. He has four of them since 2017. The world number one’s record this year reads 2-1-2 and if he can get his putter firing hot then who knows?

Reasons he won’t win: Koepka has been giving himself chances to shoot a really low score all week but has been blowing cold with the flatstick. It could ultimately prove his downfall here.

Justin Rose:

Reasons he’ll win: You don’t become a major champion and a world number one for nothing. It’s undoubtedly a tall order but having come so close at Carnoustie a year ago, Rose will be focused on producing the round of his dreams.

Reasons he won’t win: Just the sheer volume of variables he will need. Lowry and Fleetwood will have to drop back, the weather will have to not be quite as bad as expected, and even if those things happen he will have to outplay Koepka.