A pair of gritty opening day performances from Queenslanders Cam Smith and Jason Day have kept Australian hopes of winning The Open alive.

Cameron SmithBoth men took to the course in the thick of the opening round’s worst conditions but battled all day to walk off Royal Portrush’s testing links with just one bogey apiece and a 1-under 70 to their name.

They’ll enter Friday’s second round four back of outright leader JB Holmes but with their dreams of lifting the Claret Jug still intact, more than can be said for many of golf’s biggest stars.

“That’s probably where my game should be. I felt as though I left a couple out there, even,” Smith said.

“I had a few putts that went over the edge so everything was pretty solid.

“Just knowing that I can stand over a shot and not have a million thoughts going through my head, I've just got a bit of a clearer mind.”

Smith’s only dropped shot came on the uphill par-4 1st as the heaviest of the morning’s rain began to tumble.

But the Queenslander knuckled down from that point, taking advantage of the par-5 2nd for birdie before a gutsy string of seven straight pars.

Another birdie at 10 saw Smith join Day as the only Australians to reach the red numbers on the day before the World No.42 produced another run of eight pars on the way back to the clubhouse.

“It seemed like one second it was calm and hot and the next second it was cold and windy. We had a bit of everything today,” Smith said.

“It was nice that I made a couple of good saves through the middle there to keep the momentum going. I felt as though I had enough in the bag to make some birdies, they just didn't really drop.”

Despite their identical returns, if Smith and Day have dinner reservations together tonight there might be very different moods at the table, with former World No.1 Day’s only dropped shot coming on 18.

It was a rock-solid start to The Open for Day, the World No.18 making birdie at the downhill par-4 5th before picking up another stroke on 9.

A series of solid up-and-downs kept him within striking distance of the top-10 before a pulled 3-wood off the 18th tee set up a long approach shot into the par-4 and eventually a closing bogey.

Fellow Queenslander Jake McLeod was the next best of the Australians, the major debutant carding a 5-over-76 to stay in touch with the cut line at Royal Portrush.

Warrnambool’s Marc Leishman drew on all his experience in the testing conditions but could only muster an opening 7-over-78, the Victorian bitterly frustrated with his efforts.

“Just a frustrating one, the hole looked very small,” Leishman said.

“I actually drove it good enough to have a really good score and normally the strength of my game is my irons and they were pretty pitiful today to be honest.”

“I deserved a lot of the stuff I got.”

Meanwhile it was a tough initiation to major championship golf for 28-year-old Dimi Papadatos.

The New South Welshman was another to play the majority of his round in the day’s worst conditions, eventually signing for a 12-over 83 to be near the tail of the field.

Papadatos won’t have to wait long for redemption at Royal Portrush, he’s the first Australian on course tomorrow, off at 6:57am local time (3:57pm AEST) on Friday.

McLeod will be two groups further back, off at 7:19am local time (4:19 AEST).

Earlier, Adam Scott carded a 7-over 78 to all but eliminate himself from the weekend’s action on a day where not much fell his way.

There weren’t many around to see it, but JB Holmes stole the show – and the outright lead – extremely late in the peace on Thursday at The 148th Open.

Ireland’s Shane Lowry sat atop the leaderboard for the majority of the opening round after dominating in the morning en route to a first-up 4-under-67.

But five-time PGA Tour winner Holmes made three birdies in his last seven holes on his way to an opening 5-under-66 and a one-stroke buffer over the field.

A monster pack of 13 players sit one stroke further back at 3-under, a number of those defying the afternoon’s brutal winds and rain to set up a big move up the standings on Friday morning.

Arguably the most impressive effort of that group came from Kiwi Ryan Fox, the long-bomber sitting at 3-over on the 13th tee before rattling off an incredible six birdies in his last seven holes.

Joining Fox at 3-under are Alex Noren, Webb Simpson, Sergio Garcia, Kiradech Aphibarnrat, Tommy Fleetwood, Brooks Koepka and Jon Rahm to name a few.

Justin Rose leads a trio of players one stroke further back at 2-under-par.

Past Open champions Henrik Stenson, Jordan Spieth and Louis Oosthuizen are joined at 1-under in a share of 20th by Rickie Fowler and Eddie Pepperell, as well as a host of the game’s biggest names.

But the opening day at Royal Portrush may be remembered for a series of surprise implosions, none bigger than that of national hero Rory McIlroy on the first hole of the day.

The 30-year-old pulled his opening tee shot out of bounds left and it only got worse from there, the Northern Irishman recording a quadruple-bogey eight in a nightmare start.

He played the next 14 holes in 1-under-par but a double at the par-3 16th - due to a three-putt from less than two metres - and a triple bogey at the last put a full stop on a bitterly disappointing day.

Fourteen-time major champion Tiger Woods won’t be feeling much better when his head hits the pillow tonight, the American stumbling to a round of 7-over-78 that featured just one birdie.