Cam Smith says Southern Hills has raced to the top of his favourite Major venues outside of Augusta National after shooting himself into PGA Championship contention with a red-hot performance from tee to green.

Smith fought back after a sloppy start to the opening round to post a 68, and at two-under-par he sits just three shots behind first round leader Rory McIlroy (65). Smith’s playing partner Will Zalatoris (66) and Tom Hoge (66) were` one shot behind McIlroy at four under.

World No.4 Smith said he instantly fell in love with the layout at Southern Hills, a golden age design in Tulsa, Oklahoma which shares similarities with a Melbourne Sandbelt course courtesy of several shared fairway bunkers, wide open fairways and boldly-sloped greens.

“It’s my favourite Major championship course we’ve played so far outside of Augusta National,” Smith told Australian Golf Digest after his round. “I just love the way it makes you think backwards from the green to the tee shot.”

Starting from the 10th hole on day one, Smith dropped two shots on his opening nine. “But then I had a mental reset; I just had a drink of water and basically told myself, let’s start over,” he said.

It worked, because the 28-year-old rattled off three straight birdies from the first hole before adding two more and a bogey to lock up a strong start to the year’s second Major.

“It’s nice to get through (a challenge) early in the week; it was definitely one of those rounds that could have got away from me quite quickly,” he said. “If I had another couple over on (my) back nine, I’m probably out of the golf tournament. So it was nice to rally.”

Smith also revealed to Australian Golf Digest his driving had turned a corner. Smith spent a week testing and fine-tuning his driver at home in preparation for the PGA Championship, which usually favours the big hitters.

Wayward tee shots were what cost Smith a chance at a Masters victory last month, where he finished tied for third. On Thursday at the PGA, he hit an impressive 11 of 14 fairways, which freed up his irons and Smith ranked No.1 in the field for approach play.

“Today was the best I’ve felt with driver for a very long time,” Smith said. “I did a lot of work with it last week because I knew the PGA Championship is always a challenge off the tee.

“I changed shafts and found out a few things about my setup. I added loft to my driver. Even though I’ve lost 3 or 4 metres of carry distance, it’s much straighter. If I can continue to drive it like today, that’ll be key to having a chance on Sunday.”

Smith’s countryman Lucas Herbert posted a 68 in the afternoon to join him at two under. The big-hitting Victorian got as low as four under but two late bogeys brought him back.

“Couple of mistakes coming in but I still would have taken two under if you’d offered me that before the round,” Herbert told Australian Golf Digest. “Two under is a great start and it means I haven’t left myself too much work to do to get into weekend contention”

Despite making four bogeys, Herbert’s six birdies confirmed there were plenty of opportunities he could take with his sublime length off the tee. One of them was a crafty chip in for birdie at the par-4 third.

“Through the bag, most parts of my game were better today than they’ve been lately,” Herbert said. “There was a lot of pleasing stuff in the game that gives me confidence going into the next three days.”

Herbert waits on the tee during his first round.

Of the other Australians, 2015 PGA winner Jason Day (71) was one over, Cam Davis (72) and Marc Leishman (72) were two over, Matt Jones (73) and Min Woo Lee (73) were three over. Adam Scott (77) struggled and finished at seven over.

Kiwi Ryan Fox (70) was even par.