Chawalit signed for a four-under-par 68, his third successive round in the 60s this week, and a 15-under total of 201 to overhaul overnight leader Kiradech, who fired a 71 in the Asian Tour's season opening event.
After birdies at the first and fifth, Chawalit took the lead at the $300,000 event with a birdie at the par four 12th, the start of three-in-a-row which opened up a two-shot advantage.
However, he hit a stumbling block on the 16th where he dropped shot for only the second time this week at the Royal Mingalardon Golf and Country Club in Yangon, double-bogeying after finding the left rough at the par four to fall back into a tie with Kiradech.
The laid-back 38-year-old bounced back, though, to hole a lengthy putt for birdie at the par-five last and take a slim lead into Sunday's final round where he will seek his fourth Asian Tour title and first since the 2011 Queens Cup on home soil.
"I want to win but this golf course favours the long hitters like Kiradech. He is such a good player and I have so many other talented players trailing closely behind," the world number 438 said.
"Overall I played okay except for two bad holes. But I'm happy with how I played. I followed my game plan and it seems to be working. I'm lucky I had that 15 footer birdie on the last to hold the lead."
Kiradech, who lost in a play-off last year, shot his worst round of the week after opening with a 64 and then a 67.
The former car racer, who is recovering from a thyroid problem, was optimistic about his chances of adding to his sole Asian Tour title, the 2011 Sail Open.
"You must have one bad round in four days of golf," the 23-year-old who also plays on the Japan Tour said.
"I controlled my round and was happy with a one-under. Today was quite windy so that's why you don't see many low scores," the world number 209 said.
Chapchai Nirat completed the Thai stranglehold on the Myanmar leaderboard by firing a 67 to vault up into a tie for third with Filipino Angelo Que (66).
Hawaii-born Thai Arnond Vongvanij (69) is three off the lead in joint fifth alongside Australian Darren Beck (69) and India's Rahil Gangjee (67).