(Photo credit: Bill Streicher-Imagn Images)

NEWTOWN SQUARE, Pa. -- The PGA Championship saw exactly one round of 65 and one 66 over the course of the first two rounds at Aronimink Golf Club.

Before 2 p.m. local time Saturday, three players had posted 5-under 65s: Chris Kirk, Norway's Kristoffer Reitan and Englishman Justin Rose.

Another low round was in the works, as Rory McIlroy of Northern Ireland had six birdies and one bogey through 15 holes to tie the 36-hole leaders at 4 under par.

After two days of conversation about untenable pin locations and surprisingly challenging conditions, Aronimink Golf Club was open for business on a sunny Saturday afternoon in the Philadelphia suburbs.

Kirk, in fact, was one birdie away from shooting the sixth round of 62 in major championship history. After leaving his approach at No. 18 short of the green, though, he took out his putter and sent his ball 8 1/2 feet past the pin. He failed to save par, then his short comebacker hit the lip and a gasp ran through the crowd as Kirk carded his double-bogey 6.

'When I'm not playing particularly well, I tend to play more conservative. When I'm having a nice day and making putts, I'm going to try to keep the pedal down as long as I can,' Kirk said. 'I was trying to make that putt from the front fringe on 18. It just doesn't always work out that way.'

You'd forgive him for being aggressive. Kirk, Reitan and Rose each started the day 3 over par for the championship, inside the cut line by one stroke. They needed to put the 'move' in 'moving day.'

'I'm hoping the lead doesn't stretch more than 6 or 7 (under),' Rose said. 'That's kind of what I'm kind of sitting here hoping. I think, if you don't get off to a fast start, then you're going to kind of get to, let's say, the seventh hole, eighth hole, and you're going to be like, geez, you know the easy holes are running out.'

To wit, Kirk and Rose did most of their damage on the front nine. Rose went out in 5-under 30 with birdies at Nos. 3, 4, 5, 6 and 9. Kirk had five birdies in a six-hole stretch before bogeying the tough par-3 eighth.

Reitan got to 65 another way -- he eagled the par-4 13th and par-5 16th holes. The PGA of America moved up the tee at No. 13 Saturday, making it a drivable 292 yards; Reitan's tee shot hit the pin with some momentum before settling to 6 feet for an easy eagle.

The 28-year-old Norwegian just won last week's Truist Championship for his first PGA Tour title. He, Rose and Kirk agreed on the two main factors making Aronimink scorable today: pin positions that are less diabolical, and warmer weather with less wind than Thursday and Friday.

'I think they're probably halfway responsible, both of those two factors,' Reitan said, before warning that the weather may not stay that way all afternoon.

'I don't know how it's going to look like this afternoon, but happy to get out early and try to take -- or take advantage of the early morning conditions.'

World No. 1 Scottie Scheffler called the PGA of America's pin locations 'absurd' Friday, adding that he felt they are the toughest he's seen since turning pro. Some were positioned on small shelves within a green or on a tricky slope.

'Pin locations is a big difference, for sure,' Kirk said Saturday. 'There's a handful of really tough ones out there still, but for the most part, they're much, much more accessible than they have been the last few days.

'It is warming up, and I think that makes a big difference,' Rose added. 'Suddenly the ball is going a bit further. I think players feel a little bit better in T-shirts, and the body works a bit better, people start hitting the ball a little bit further.'

Second-round leaders Maverick McNealy and Alex Smalley are scheduled to tee off at 2:40 p.m. local time. Others making a move up the leaderboard in the meantime were Xander Schauffele (4 under for his round, 3 under for tournament) and Spaniard Jon Rahm (-3, -2).

--Adam Zielonka, Field Level Media