Australian golf has endured its worst British Open golf championship in the modern era after Marc Leishman failed to spare the green 'n gold blushes on the final day at Royal Portrush.

The 41-year-old LIV golfer, the only one of nine Australians to make the cut in a dismal display at the 153rd Championships, had a final-day struggle in almost ideal weather conditions at the Dunluce links, shooting a four-over 75.

It left the Victorian veteran tied for 52nd place at level par for the week. 

Since Peter Thomson became the first Aussie champion in 1954 at Royal Birkdale, that's the worst position for the leading Australian at the Championships in any of the subsequent 71 editions.

The same Portrush course in 2019 was the only other occasion during those years when just one Australian made the cut (out of six starters), but at least the survivor, Cameron Smith, earned a top-20 spot that day.

Over the years, it's become fairly commonplace for an Australian to be featuring in the last-day shake-up for the Claret Jug, but in this century, the worst Open for the Aussie challenge was 2001 at Royal Lytham when Richard Green was the best-placed, tied for 42nd.

Then, though, there were five Australians playing the last day, while Leishman was the lone survivor this time.

He had set off just outside the top 25, hoping to shoot "something silly" in a bid for a top-four finish that would seal him a place at both next year's Masters and the 2025 Royal Birkdale Open.  

Light winds and lovely weather promised much on Sunday but Leishman started going the wrong way once he drove into a fairway bunker at the fourth, found the thick stuff at the next and another fairway sand trap at the ninth to record bogey fives.

"I just drove in a few too many fairway bunkers during the week," he admitted. "There was a few holes where I took them on purposely, knowing that if I hit an iron, there's still going to be one in play. If I was going to take it on, I thought I might as well take it on with the driver. A few of them didn't come off."

A couple of birdies straight after the turn were sandwiched by another five at the par-four 11th, before his biggest calamity occurred at the short 13th when he blasted out of one greenside trap straight into another across the other side of the dance floor. A double-bogey five was the result. 

"Some days you have it, and some days you don't," sighed Leishman. "Today I didn't. Disappointing day. 

"You have days like that sometimes, and obviously you don't want them to be on Sunday of a British Open."

"So, disappointing, but take the good with the bad. Onwards and upwards from here."

Leishman said he was now looking forward to a break with his family. "Probably do a little tour of Dublin with the kids -- and do another tour of Dublin later in the night-time, us boys," he smiled, dreaming of another Guinness.

Then he'll feature in next week's LIV Golf event at the JCB Golf & Country Club in Staffordshire, after which he has his eyes set on an end-of-year assault on the two big Australian titles he's never won: the PGA at Royal Queensland in November and the following month's Open at Royal Melbourne. 

"Hopefully, this is the year," he said.