KUALA LUMPUR, 1 Nov, 2014 (AFP) - Na, who is looking for his second career victory on the PGA Tour, was one of three players in the field to record a bogey-free third round.
Sergio Garcia and Billy Hurley, who led on Friday, trail a shot behind going into Sunday's final round.
Defending champion Moore, known for his unorthodox swing, surged top of the leaderboard courtesy of seven birdies, including the tricky 11th and 12th hole -- the highlight of the 32-year-old's play.
"I birdied 11 and 12, two of the toughest holes on the course back-to-back. I just hit a great shot into 11 with a hybrid to maybe 20 feet or so, and followed up into 12 from maybe 25, 28 feet," said Moore.
"That was the highlight for me and gives me that extra confidence going into Sunday. I know what it's like to win out here, and I'm going to try and make it happen again."
Moore, who defeated Gary Woodland on the first playoff hole to win the CIMB Classic in 2013, is looking to become the first in the tournament's history to defend his title.
Garcia -- who stayed in contention for a second title after his Qatar Masters victory in January this year -- was a consistent performer, with five birdies to card a 68.
The Spaniard blemished his scorecard with a bogey on the 11th after a two-hour delay due to rain showers at the Kuala Lumpur Golf and Country Club, but remains confident going into the final round.
"I obviously have to play a little better than I did today, but I'm in contention to win another title, so I'll go out there and give it my best shot and try to be aggressive and positive," he said.
"If I can manage that, I should have a chance of winning."
Lee Westwood, who shot a hole-in-one to card a low 65 on Friday, fell off the pace with five bogeys to reach a two-over 74.
The former world number one's gloomy showing on a wet day in Kuala Lumpur sits him seven shots off the top.
Leading third-round scores on Saturday in the $7 million CIMB Classic at Kuala Lumpur Golf and Country Club: (Par 72)
204 – Kevin Na (USA) 69-68-67, Ryan Moore (USA) 68-69-67
205 – Sergio Garcia (ESP) 69-68-68, Billy Hurley III (USA) 67-67-71
207 – Gary Woodland (USA) 71-70-66, Bae Sang-Moon (KOR) 71-68-68, Kevin Chappell (USA) 69-68-70, Kevin Streelman (USA) 68-68-71
208 – Brendon de Jonge (ZIM) 70-73-65, Patrick Reed (USA) 70-70-68, Angelo Que (PHI) 67-72-69, Cameron Smith (AUS) 70-69-69, Jeff Overton (USA) 68-69-71
209 – John Senden (AUS) 72-68-69, Prom Meesawat (THA) 68-71-70, Noh Seung-Yul (KOR) 68-69-72
210 – Davis Love III (USA) 68-71-71
211 – Greg Chalmers (AUS) 75-68-68, Danny Lee (NZL) 69-69-73, Brian Stuard (USA) 67-72-72, Lee Westwood (ENG) 72-65-74