Finishing at twilight, Day shot 5-under 66 and looked to be in the form he had in 2015 when he won the PGA Championship.
Kisner admitted he's upset about how he's played in the majors, having yet to record a Top 10. However, a double bogey on the tough No. 3 par-4 set him back in an otherwise solid over-par round.
Day was forced to race the sun to finish the final four, making par on all of his remaining holes.
Despite a shaky start, Day nailed an eagle on the seventh and followed it up with three consecutive birdies to end his round in outright third and just two shots shy of leaders Kevin Kisner and Hideki Matsuyama.
"He said, 'No, let's birdie the last three.' So I was able to do the first part. I just got distracted on 17 tee and made a bad swing and hit a bad shot and ended-up making a triple bogey".
"But to be honest, I felt like this was always - it's been slowly building". "Even if they didn't do anything else with the golf course and just changed it to full bermuda like it is now, all of a sudden makes the golf course two shots more hard".
"Right now, I'm just keeping one foot in front of the other", he says matter-of-factly. It's a tough golf course.
"You know, we'll see. You know, create a little bit of hype before the season starts again".
"These guys going out this afternoon, they break 70, they've done a hell of a job, " McIlroy said after a 73 that put him 10 shots back.
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"The first 15 holes, especially, I was driving the ball very, very well and that made it a bit easier", said the world No. 78, a four-time European Tour victor. Managed to keep it in play a lot better today.
"I don't think I was as free rolling as I thought I would be, as you can tell by some frustration", he said. "So it was nice to see that one drop".
If the answer is no you need to take a long, hard look at yourself.
"I played OK after that but I wasn't fusing it off the tee, and I had to scramble a bit off the tee". I've got nothing to lose. At the time, though, Hideki Matsuyama was coming on strong, and he finished with a 7-under 64 before darkness stopped play for some players.
Walker said he would welcome an offseason, if only so the schedule could save him from his competitive self, which struggles to sit out a tournament (or a few) because he worries he will fall behind in the points race for the FedEx Cup playoffs.
Omar Uresti is the only club professional expected to make the cut in the 2017 PGA Championship.
It was an early moment of magic from the world No 4 but there was precious little else to cheer until he scrambled away from the cut line with those late birdies.
The rough was McIlroy's biggest problem yesterday as he hit just seven fairways and left himself an average of 54 feet from the hole. Cameron Smith has three holes to play but at 13-over is very unlikely to progress.
The PGA Championship is over for New Zealand's Danny Lee (12-over), Rod Pampling (14-over) and Stuart Deane (23-over).