Reigning champion Kim shares PGA Vegas lead with Hadwin and Griffin
The South Korean birdied four of the last six holes to stand alongside Canada's Adam Hadwin and American Lanto Griffin on 15-under 198 after 54 holes at TPC Summerlin in Las Vegas.
Kim, a runner-up in this year's British Open at Royal Liverpool, made nine birdies in all plus an eagle against two bogeys after starting the day six strokes adrift.
"It was great. It's not bogey-free but it's still nine-under par," Kim said. "I played great today.
"I got into that place where I was comfortable and I was very calm. I didn't feel like I was rushing into anything. I was just really in my place.
"I had a lot of good shots. I had a lot of good looks. I left myself in some tough situations but recovered really well."
Hadwin, who began the day five off the pace, fired a bogey-free 63, his eight birdies including a tap-in at the par-5 16th after driving the green in two and another at the par-3 17th after landing his tee shot within three feet of the hole.
"I was a little off early," Hadwin said. "I chipped in on one to settle things down. I had a great up and down from just behind the green on three as well.
"And then I started hitting some really good shots. I 'flushed' it out there. I've been hitting it really well for three days. Made a few more putts today."
Hadwin's only PGA victory came at the 2017 Valspar Championship but he lost a playoff to American Rickie Fowler in July at Detroit.
Griffin, a 36-hole co-leader whose only PGA win came at the 2019 Houston Open, began with 12 pars then birdied three of the last six holes to fire 68 and stay at the top.
"That was frustrating. I was hitting good putts but they weren't quite right," Griffin said of his birdie-free start. "They were just all on the edges. Just tried to hang in there.
"I'm pretty proud of myself for hanging in there on the back and giving myself a shot for tomorrow."
Kim seeks his third career PGA title after triumphs in last year's Wyndham Championship and in Vegas, where he won by three strokes and also fired 62 in the third round.
"Nice to come back here the next year and shoot the same score as I did last year in round three," Kim said.
"I didn't try to force anything. I just tried to hit the best shots I can and if it works out great. I'm glad it worked.
"Whatever happens, I'm glad I gave myself a chance tomorrow."
Canada's Taylor Pendrith, South Korea's Lee Kyung-Hoon and American Vince Whaley were one stroke back sharing third on 199.