Kiradech birdied three of his last four holes for an 11-under total of 205 at the Kuala Lumpur Golf and Country Club.
Davies shot a 71 with a round that included three birdies and a double bogey.
Two-time champion Thongchai Jaidee of Thailand, Soren Hansen of Denmark and Koreans K.J. Choi and Noh Seung-yul were one shot behind.
Kiradech nearly made the first hole-in-one of the tournament when his six-iron tee shot on the 15th ended up an inch behind the hole. He continued his strong finish with birdies on 17 and 18.
Davies, who played 25 holes on Saturday, had two birdies on the front nine. After a double bogey on 10 - the result of an errant drive into the water hazard, he fought back with a birdie on 17 and then missed a birdie chance on the last for the outright lead.
Thongchai mixed five birdies with two bogeys for a 69 in his bid win a record-equaling third victory in the event, which is co-sanctioned by the Asian Tour and European Tour.
Choi is aiming for a Malaysian double after his victory in the Iskandar Johor Open last October, and put himself back in contention with a 69.
In Gold Coast, Australia, Karrie Webb put herself in a strong position for a seventh ANZ Australian Ladies Masters title, shooting an 8-under-par 64 on Saturday to take a one-stroke lead after three rounds.
The Australian's total of 15-under 201 put her a shot ahead of compatriot and defending champion Katherine Hull (65) and South Korean Lee Bo-mee (63). Those three will be in Sunday's final group, pitching Hall of Famer Webb against the woman tipped to succeed her as Australia's dominant female player.
Webb was in a fairway bunker on the final hole but hit a 6-iron cleanly out of the sand about 140 meters, over a tree and to the green and sank the 15-foot putt.
Organizers say they are considering Lee's 63 a course record because they changed two tee boxes this year. But a 62 shot by Australian Kristie Smith in the tournament last year is the lowest score shot on the course before it was lengthened slightly.
Two South Koreans were tied for fourth after shooting 66s - Seo Hee-kyung and Ryu So-yeon - on a Royal Pines resort course softened by rain and made easier by the lift, clean and place rule used in the first round.
Former American amateur star Amanda Blumenherst, who led after the first two rounds, shot 70 Saturday and was tied for sixth, four off the lead and level with Taiwan's Yani Tseng (67).
Lim Ji-na, who shared the second-round lead with Blumenherst, shot 75 and was tied for 25th, nine shots behind Webb.
In Miami, American Anthony Kim fired a sparkling six-under 64 to grab a share of the lead with Colombia's Camilo Villegas after the second round of the Honda Classic on Friday.
Kim notched seven birdies and a single bogey to share the day's lowest round on a cool but calm day at the PGA National Champions course in Palm Beach Gardens.
Kim joined Villegas on an eight-under total of 132 after the in-form Colombian set an early target by returning a four-under 66 for the second straight day.
Former world No.1 Vijay Singh finished one stroke adrift after shooting a 66.
The big Fijian had looked headed for a rough day after back-to-back bogeys on the fifth and sixth holes but played flawless golf the rest of day to sit alone on seven-under 133.
Singh, playing free of the back and knee pain that plagued him last season, was unlucky to miss a share of the lead after rolling in a monster 65-foot birdie putt on the 17th, but leaving a 12-foot birdie hanging on the lip on 18.
American Jerry Kelly is two off the pace after a five-under 65 while a group of five are three back including overnight leader Nathan Green of Australia (70), Canada's Mike Weir (64) and Briton Graeme McDowell who was handed a costly penalty after his round.
After landing his tee shot on the 18th in shallow water, McDowell attempted to blast his ball out but grazed the surface on his back swing. He informed officials and was penalized two strokes to leave him at three-under 67.
Yang Yong-eun, who claimed his first PGA crown at last year's tournament, saw his title defense end dismally when he missed the three-over cut by six shots.
The South Korean's even par 70 was not enough to recover from his horror-opening round of 79.
