Cameron Smith duffed his tee shot horribly in near-darkness at 6.57am -- and the day never got much better for Australia's British Open Championship battalion over the next 14 hours as they're already being forced to play catch-up at Royal Portrush.

The mildly embarrassed 2022 champion Smith could hardly credit his scuffed effort at the first hole of the 153rd Open trickled, perhaps fittingly, a mere 153 yards into some rough stuff down the left. It wasn't even far enough to reach the fairway on a demanding Thursday morning on the Northern Ireland links.

But credit to the mulleted rugby league fan, he bounced back after labouring to the turn at three over and then scrapped, summoning up what he hailed as "a bit of Queensland spirit" as he fought to a one-over 72.

"I think I tried to hit that one underground - and almost missed it," sighed Smith. "Not the greatest start to a major championship I've ever had."

Yet he could still hardly have imagine that not one of the other eight Australians to follow could improve on his round, with none managing to break par.

That was in stark contrast to the rest of the field, with 29 players able, either side of a couple of hours of dreadful rain-swept, windy conditions, to finish in the red figures as the day approached its conclusion.

They were being headed by the quintet of Denmark's Jacob Skov Olesen, China's Li Haotong, Britain's former US Open champion Matt Fitzpatrick, South African Christiaan Bezuidenhout, and American Harris English, who all shot four-under 67s.

Even Adam Scott, who like Smith began with a workable 72 a day after his 45th birthday, admitted the green and gold contingent will need to get to work fast on Friday to drag themselves back into the fray.

Asked if he was still in the hunt in his 25th consecutive Open and 97th straight major, 'Scotty' mused: "I mean, kind of. It could have got away. I'm not out of it, but I'm going to have to have a good morning tomorrow. Hopefully, the weather cooperates."

That's the imponderable. Jason Day, who also had to battle with a fine inward nine to get back to two-over for his round, was left tearing his hair out about the ever-changing climate, featuring heavy rain, gusty winds and sunshine, .

"It's the craziest weather pattern I've ever experienced in my life here. There's no consistency to it whatsoever. I'd love to be a weatherman here. You just get it wrong all the time!" bemoaned the 2023 Open's joint runner-up at Hoylake. 

Not that he was happy with his game. "To work hard coming into this week and then to go out there and have poor process is not acceptable, especially in my eyes," said Day, who at least won the fashion stakes for the day with some spectacular patterned knitwear to go with his shades. 

"I've got to do a better job of it and hopefully come back tomorrow and do it again, play better."

The rest of the Aussies were left muttering something similar. In-form Lucas Herbert started brightly and was among the early leaders at two under, but four bogeys over the last eight holes left him with a three-over 74.

Like Herbert and Scott, Marc Leishman was fuming to bogey the last, ending at two over, while Elvis Smylie had six bogeys in his 75 and Min Woo Lee had three straight late bogeys to finish with a 74. Curtis Luck, the last Aussie to finish, was six over after 14.   

Ryan Peake's big adventure in his first major went somewhat awry as he ended with a six-over 77.

The Australian former motorcycle gang member, who turned his life around through golf after spending time in prison for assault, has been the centre of much attention at Portrush this week after gaining his place thanks to a fairytale win at the New Zealand Open.

Partnering former champion Phil Mickelson, 31-year-old Peake ended up getting the six-time major winner to sign his glove and to give him his ball after the round.

Peake's fellow "Lefty'' Mickelson recorded a one-under 70, while the Perth debutant struggled, admitting: "I just got beat up out there."