The opening round of the 2019 US PGA Championship has lived up to expectations as players took to the challenging, par-70 Bethpage State Park Black Course in New York.

New Zealand’s Danny Lee impressed in round one, sitting just one shot behind leader and reigning champion Brooks Koepka at Bethpage Black after recording a score of 6-under the card.

Firing his lowest score ever in a Major, birdies on 17 and 18 helped Lee recover from a bogey on 15 to be well in the mix ahead of round two where he sits three shots ahead of third-placed player Tommy Fleetwood.

“Whenever I hit it on the fairway I gave it a good look for birdie,” said Lee post-round. “I made those putts and it was a good round today.”

“Mainly I’ve been focussing on my body getting stronger so I can add more speed on my swing,” Lee added after admitting he had worked on many aspects of his game ahead of the tournament.

“I’ve been changing my swing a little bit and working really hard with George Gankas who is known for making players hit it further and I think I gained about a good 15 yards more which has been great.”

Jason Day was the best Australian on-course in round one, firing 1-under the card to sit alongside a logjam of eight players tied for 9^th place.

In what was an up and down round for Day, back-to-back birdies on the 11^th and 12^th holes saw the 2015 PGA Championship winner recover from a bogey on 10 and a +2 scorecard while a further birdie at 16  moved him to under par.

“It was a little bit frustrating after I hit a good pitch just out of the rough on 10 to miss that short one,” said Day.

“To hole a good momentum putt on 11 was good but I don’t know, it played really tough. I don’t know what course Brooks (Koepka) was playing but it played very difficult out there so I’m very happy to get it in at 1-under.”

“It felt like we played a big round today, maybe five and a half or six hours.”

Adam Scott was the first of the Australasians to tee off in sunny but windy conditions in Farmingdale, NY in a morning that proved challenging for the contingent.

A score of 1-over 71 has Scott sitting in T41 at the conclusion of round one, his day consisting of birdies at the 2^nd, 4^th and 7^th holes with bogeys coming at the 6^th and 10^th as well as a double-bogey at the par-3 8^th.

Australian PGA Championship winner Cameron Smith carded a relatively steady round to enter the clubhouse with a score of 3-over 73. Following a lone birdie on the par-5 4^th hole, bogeys at 5, 6, 10 and 17 allowed Smith to stay close to the leaders following what was a challenging day for many.

In his maiden appearance at the US PGA Championship, Lucas Herbert maintained his composure on the notoriously tough layout, firing birdies at the 4^th and 10^th holes and bogeys at the 2^nd, 4^th, 6^th, 7^th, 9^th and finally the par-4 12^th.

No further blemishes appeared on Herbert’s scorecard from the 12^th, an impressive note for the 23-year-old to take into round two.

Marc Leishman endured a number of tough shots throughout round one at Bethpage Black to also sit at T91 with a scorecard of 4-over. As conditions cooled in the afternoon, play became harder for the Victorian, who went from even par to +4 across the back-9.

It was all bogeys for Brendan Jones, whose round one score of 8-under echoed that of Kiwi Ryan Fox with the duo sitting at T144 on the leaderboard.

Australian PGA Professionals Stuart Deane and Craig Hocknull completed their rounds tied for 153^rd with a scorecard of 12-over.

Round two of the 2019 US PGA Championship begins at 8:45pm AEST.

Round 1 standings:
Danny Lee           6-under 64
Cam Smith           3-over 73
Marc Leishman    4-over 74
Jason Day            1-under 69
Adam Scott          1-over 71
Lucas Herbert      4-over 74
Brendan Jones     8-over 78
Ryan Fox              8-over 78
Stuart Deane       12-over 82
Craig Hocknull     12-over 82