Australian big guns Adam Scott and Jason Day failed to fire in the opening round of the US Open.

World No.1 Adam Scott and No.7 Jason Day failed to live up to their lofty rankings in the opening round of the US Open at Pinehurst No.2, falling eight shots off the pace.

While former No.1 Martin Kaymer was in a class of his own on his way to a five-under par 65 and a three shot lead, Scott and Day struggled to rounds of 73 to be eight shots back and tied 67th.

Germany’s Kaymer, the 2010 PGA Championship winner and recent victor of the Players Championship, cemented a three-shot buffer with three birdies in his final five holes, skipping clear of Americans Kevin Na and Fran Quinn, 2010 US Open champion Graeme McDowell of Northern Ireland and Zimbabwe’s Brendon De Jonge.

“I just didn’t make many mistakes. I hit a lot of good golf shots and finally I could make some putts,” Kaymer said.

A host of big names shot 69 to be tied sixth including world No.2 Henrik Stenson, Brandt Snedeker, Keegan Bradley, Dustin Johnson, Matt Kuchar and young guns Jordan Spieth and Hideki Matsuyama.

Aaron Baddeley was the pick of the Australians, fighting back from a triple bogey on the opening hole to post an even-par 70, leaving him tied for 16th. But the big pre tournament favourites Scott and Day were far from their usual best.

Day battled his swing for the entire round and could have easily scored much worse if not for his fighting spirit around the greens.

“If I didn’t have my short game I would have been in the 80s somewhere. I am glad I got up and down a lot and there is still three days ahead of us,” Day said.

“I was a little loose throughout the whole round. I just didn’t hit it as good as I needed. I am not too disappointed with how the round went considering how bad I hit it.”

For Scott, his ball-striking was better than his fellow Queenslander, although also shonky on occasions, but his short game wasn’t crisp enough.

“I’m a little disappointed. I think I played a little better than what I ended up shooting,” Scott said. “Around this kind of golf course, I just put it down to my short game not being spot on.”

Both men refused to be discounted despite the hole they find themselves in, vowing to make a move on Friday.

“It would be nice to move the other way tomorrow and get myself in good shape starting out Saturday,” Scott said.

“If the conditions are the same, I’d like the play the course in a similar way I did today and I think I can shoot five or six shots better.”

Oliver Goss, likely playing for the last time as an amateur, produced an impressive round of 71 to be on track for low amateur honours for the second major in a row.

“I am pretty happy with one-over even though I left a couple out there so there is room for improvement,” the 20-year-old Goss said.

Veteran John Senden joined Goss at one-over while Geoff Ogilvy and Rod Pampling joined the marquee Aussies at three-over.

Matt Jones finished with a 74 while Brady Watt (77) and Aron Price (78) found the going tough in their major championship debut.

Veteran Robert Allenby managed two birdies but had his card littered with eight bogeys and a triple bogey on the way to a 79.