2021 PGA Championship leaderboard breakdown, scores: Corey Conners on top of strong field after Round 1

Conners is two shots clear of the rest of the field through 18 holes at the PGA Championship

With Round 1 of the 2021 PGA Championship behind us, one thing that is increasingly clear about Kiawah Island is it's not for the faint of heart. The Ocean Course swallowed up some of the sport's best in the opening round of action. Justin Thomas and Rory McIlroy -- the betting favorites entering the day -- were among them. Canadian Corey Conners was decidedly not. 

Conners posted an opening-round 5-under 67 to pace the field by two strokes. He leads a loaded T2 perch on the leaderboard that features six different men at 3 under. Then there's a cadre of contenders lurking at T8, where at 2 under even more star power abounds. Reigning champion Collin Morikawa sits here ready to pounce after an opening-round 70. So, too, does 2005 PGA Championship winner Phil Mickelson. 

As for the rest of the leaderboard, here's a rundown from the first day of action at Kiawah Island.

1. Corey Conners (-5): A strong start to the day for Conners never really trailed off. He opened with three birdies through seven and overcame a bogey on No. 9 by turning in a clean back nine featuring birdies on 11, 15 and 16 without any bogeys. He was remarkable tee to green and cleaned up nicely with the putter to boot. Conners' best-career finish at a major came earlier this spring with a T8 at the Masters, and he showed Thursday -- weathering windy and challenging conditions -- that he's capable of contending into the weekend. It is his best position on the leaderboard after any round at a major in which he's appeared, topping his previous best of T6 earlier this year at the Masters.

T2. Brooks Koepka, Viktor Hovland, Keegan Bradley, Aaron Wise, Sam Horsfield, Cam Davis (-3): How Koepka was able to end Round 1 squarely in contention is impressive for two reasons. The first, and most obvious, is that he's physically not right. He had knee surgery on March 16. Since then, he's played in only the Masters and the AT&T Byron Nelson, missing the cut in each. The second is because of how he started the day, double-bogeying the par-4 10th. He played the remaining eight holes at 2 under and then posted a bogey-free second-nine with three birdies. He's still favoring the knee, as you can see when he bends, but he hit the ball well and led the field in strokes gained on approach.

The length of the Ocean Course is candy for great ball-strikers like Hovland, who with his opening-round 69 tied for the field lead in greens in regulation. He had only one bogey on the round. Bradley's rise to the top Thursday was no surprise, as he entered the day as one of the sneaky hot golfers on the tour after finishing second at the Valspar at T4 at the Zurich Classic. He leads the field in strokes gained tee to green and in greens in regulation. It was an impressive all-around outing and on a course that requires precision, he had it in spades. 

T8. Collin Morikawa, Phil Mickelson, Sungjae Im and five others (-2): Reigning PGA Championship winner Morikawa missed plenty of shots in his opening defense of his championship Thursday, posting three bogeys -- two on the front and another on the back. But he made huge putts to give himself chances to post scores and led the field in driving accuracy to make up for it with six birdies. Mickelson, the 2005 champion, grinded out a similar round anchored by quality driving with a 32 coming home. Pretty gutty finish after some real adversity early in which he bogeyed Nos. 4, 5 and 6.

T16. Rickie Fowler, Will Zalatoris and 13 others (-1): After a rocky year for Fowler, he's playing this week on a special exemption -- and making the most of it. He said after his round that playing money games against Michael Jordan have helped fuel him, and added he's starting to feel "pretty darn good." He's done a lot of tweaking to his game of late -- we can't gloss over missed cuts this month at the Wells Fargo and Byron Nelson -- but he looked strong in Round 1. More "go play golf" and less "play golf swing," as he put it Thursday, did him well. 

T31. Bryson DeChambeau, Jon Rahm and 7 others (E): A sluggish start to the day turned into a strong finish as DeChambeau converted an opening-nine 2-over 38 into an even-par 70. He had a stretch with four consecutive bogeys from 13-16 where it appeared he was actively ejecting, but he rallied by keeping his driver in play and hitting good shots. Spieth was a little more consistent with a 70 that could easily have been in the red if not for a few putts that lipped out. Rahm played a steady round with a pair of birdies and bogeys. He led the field in driving distance and gained 1.75 strokes on the field tee to green.

T40. Hideki Matsuyama, Jordan Spieth, Patrick Cantlay and 20 others (+1): This course is a ball-strikers dream for players like Matsuyama, the 2021 Masters champion. He wasn't quite able to take advantage, however, as his putter held him back including a three-putt on 18. Same for Spieth, though he played the final three holes at even-par, an accomplishment unto itself. As for Cantlay, Thursday he became the first player since Kenny Knox in 1991 with multiple eagles in the opening round of a PGA Championship. 

T78. Rory McIlroy, Justin Thomas and 19 others (+3): Playing together in a threesome with Koepka on Thursday, both McIlroy and Thomas struggled to find any rhythm. McIlroy struggled with the putter in particular and discovered how unforgiving the course can be with a few tricky lies with no relief. Thomas struggled off the tee, where he lost strokes to the field. Both entered Thursday 1-2 atop the betting board to win this week and while a rough first day is not a disqualifier, they're in a precarious position and need strong showings Friday to be here for the weekend.

Rick Gehman and Kyle Porter break down and react to Thursday's first round action at the PGA Championship. Follow & listen to The First Cut on Apple Podcasts and Spotify.

[May 20, 2021 at 6:51 pm ET · Kyle Porter]

Great insight from Phil about the pitch around holes at Kiawah. Said it's less severe than old-school courses so they can run the greens faster and keep it fair. Simplified what could be a complicated concept for the average fan (which is the opposite of what he usually does).

[May 20, 2021 at 6:31 pm ET · Kyle Porter]

Spieth lips out another birdie on No. 15. It's the only category where he's a negative. He's been driving the hell out of it and not scoring at all. If he can somehow play the last three in -1 to get to even, that'll feel like a win at this point.

[May 20, 2021 at 6:28 pm ET · Kyle Boone]

Corey Conners is in the clubhouse with a field-best 5-under 67. He's two strokes up on the lead. Had just one bogey all round.

[May 20, 2021 at 6:26 pm ET · Kyle Boone]

85% of the last 20 PGA Championship winners were not 1/T1 after the first 18 holes. Something to keep in mind here as Corey Conners is poised to potentially finish with a two-stroke edge on the field.

60% of winners in that span were 3+ strokes back after Round 1.

[May 20, 2021 at 6:08 pm ET · Kyle Porter]

I'm ... not sure how, but Phil Mickelson is somehow -2 thru 16 holes. It won't hold up, but he's been really impressive thus far to shoot something under par at his age with how his game has deteriorated over the last few years.

[May 20, 2021 at 5:56 pm ET · Kyle Porter]

Corey Conners gets to -5 on his round and heads to 17 and 18 with a two-stroke lead. His tee shot on 17 is solid. Should be a nice two-putt and another half-stroke picked up.

[May 20, 2021 at 5:50 pm ET · Kyle Boone]

Corey Conners with birdies on 15 and 16 to get to 5 under. Now facing a brutal gauntlet to close the day, but that might be cushion enough to make him your leader after Round 1. Will see if it holds.

[May 20, 2021 at 5:39 pm ET · Kyle Porter]

Zalatoris is making a little move here. He's at -2 and has a chance to threaten the lead late today. However, even if he plays even par the rest of the way in, that would be fantastic with the hardest holes on the course looming.

[May 20, 2021 at 5:26 pm ET · Kyle Boone]

Corey Conners is now your solo leader after a birdie on No. 15. He made the turn with a bogey on No. 9 but has played an overall clean round, with birdies on 2, 5, 7 and 11 as well.

[May 20, 2021 at 5:13 pm ET · Kyle Porter]

Spieth just missed a short putt for par to get his back nine started, and his putter has not been great so far. He's in danger of dropping a Rory-like 75 with the toughest holes on the course forthcoming.

[May 20, 2021 at 5:06 pm ET · Kyle Boone]

Tiny nugget on Brooks Koepka: He leads the field in strokes gained on approach through one round at 3.46. Considering he had surgery in mid-March, that he's leading the field in anything is remarkable. But that stat also comes with the fact that he's tied for the lead at a major. Still favoring the knee, but a very impressive outing on day one from him.

[May 20, 2021 at 4:42 pm ET · Kyle Porter]

Corey Conners is such a stud. He's tied for the lead at -3 thru 12 holes, and the scary part is that he's gaining most of his strokes with the putter. Normally, that's a bad thing, but for somebody like him who's legitimately a top-15 ball-striker in the world, it could foreshadow contention.

[May 20, 2021 at 4:27 pm ET · Kyle Boone]

Two eagles for Patrick Cantlay today and he's only at 1 under after a nasty stretch on the front nine. We'll see if he can launch into some positive momentum after that one on No. 7.

[May 20, 2021 at 4:25 pm ET · Kyle Boone]

Jon Rahm having a relatively quiet Round 1 today. He made the turn at even-par after a front nine 36 and just got to the red with a birdie on No. 10. Had a bogey on No. 6 and came back with a birdie on No. 7. Nothing special so far, but he's kept it in play, he's hitting the ball well and he's made a few important putts to stay within striking distance. Final few holes are playing really tough but if he can stay under-par he's in business.