Australia's Cam Davies lies three shots off the lead in a tie for 11th after a third-round 67 marked by six birdies and two bogeys.
Kim fired a nine-under-par 62 - one better than Hadwin's 63 - as both sit at 15 under after 54 holes.
The South Korean jumped 25 spots up the leaderboard on moving day while Hadwin improved 19 places.
Griffin, the co-leader after two rounds, shot 68.
Three players are one shot back in a tie for fourth, and another four golfers sit tied for seventh just two shots off the lead, including Switzerland's Callum Tarren, who matched Kim's 62 for the day's lowest round.
Tarren vaulted 41 spots up the leaderboard and into contention.
Adding to Kim's eventful round he carded two bogeys and an eagle to go with his nine birdies.
"Tee to green, I was really solid. Gave myself a lot of looks," Kim said.
"I just felt really comfortable over the ball. That was the biggest thing. I wasn't rushing anything. I wasn't trying to force anything. I was just really calm."
Hadwin, playing in his first tournament since the BMW Championship in late August, turned in a clean card with his eight birdies.
"I would like to say I was rusty, but based on the scores, I don't feel very rusty," Hadwin said.
"Certainly rejuvenated. You take that amount of time off, I was ready to come back and see where I was at and get into competition again."
Tarren fashioned a round of nine birdies and an eagle playing with Isaiah Salinda, who carded a 63 as the pair were among those tied for seventh at 13 under.
"We just fed off each other,," Tarren said.
"It was super-fun. I said to him on 18, 'This has been a good day for us both'. It's just crazy but the momentum was on our side today."
Second-round co-leader Cameron Champ shot 74, falling into a tie for 24th at nine under.
