Irishman Shane Lowry withstood miserable weather conditions and the weight of local expectation to claim his first Major title with a stunning six shot victory at the 148th Open Championship.

After posting a record breaking 63 on Saturday evening, Lowry showed a different side to his game on an extremely wet and windy final afternoon at Royal Portrush Golf Club as he posted a battling 72 to reach 15 under par and get his hands on the Claret Jug.

Tommy Fleetwood finished alone in second on nine under, with third placed Tony Finau a further two shots behind the Englishman as the chasing pack felt the full force of the afternoon conditions.

Lowry said: "I can’t believe it. This is not going to sink in for a few days. Walking down 18 I could not believe this was happening to me. I feel like I am in an out-of-body experience. I was so calm."

Beginning the day four shots clear of nearest challenger Fleetwood, Lowry made a nervy start, finding the rough and then sand at the opening hole to card his first bogey since Friday, but he was spared a two shot swing as the Englishman missed his eight foot birdie putt.

Lowry's four shot lead was restored at the par three third when playing partner Fleetwood made his first bogey of the day after failing to get up and down.

As a sell out crowd cheered him on, runaway leader Lowry extended his advantage to five strokes with a birdie on the fourth before making another gain from eight feet on the par four fifth to move to 17 under.

With the conditions getting progressively worse, Lowry lagged his 35 foot birdie putt to two feet at the sixth before notching his third birdie of the day at the long seventh thanks to his superb touch around the green.

Fleetwood was battling hard - getting his first birdie at the fifth after his ten foot eagle putt just missed the hole, before producing two great par saves on the sixth and seventh - but he could not keep pace with Lowry who moved six shots ahead.

Lowry and Fleetwood both made bogeys at the eighth after finding the rough off the tee as the rain began to pour down.

Another bogey at the ninth - after getting into more trouble off the tee - saw Lowry slip to 16 under but he stopped the rot with a solid par save from six feet at the tenth.

And with Fleetwood missing his par putt from four feet at the same hole, Lowry's lead was back to six shots.

Lowry made another bogey at the 11th after missing his downhill putt from seven feet and, after parring the 12th, saw his lead reduced to four when Fleetwood rolled in his birdie putt from close range.

After both men safely parred the 13th, Lowry dropped his fifth shot of the day at the next but saw his five shot lead return as Fleetwood double bogeyed.

A bounce back birdie at the 15th put Lowry, who won the 2009 Irish Open as an amateur in similarly poor weather, six clear with three holes left to play and he safely parred the 16th, 17th and 18th to become the Champion Golfer of the Year.

"It's just incredible to be sitting here with a trophy in front of me. Look at the names on it," Lowry added.

"I hit my tee shot on 18, that was it, and I started to enjoy it then. It was just incredible to walk down 18. The crowd was going wild. I tried to soak it in as much as I could.

"I didn't even know going out this morning if I was good enough to win a Major. And look, I'm here now, a Major Champion. I can't believe I'm saying it, to be honest."

Lee Westwood and Brooks Koepka finished in a tie for fourth on six under as Royal Portrush showed its teeth.

Francesco Molinari signed off his year as Open Champion in style with a bogey free 66 to finish on three under par, with 22-year-old Scot Robert MacIntyre two shots better off after completing his Major debut with a closing 68.