The 25-year-old Choo, touted as one of the region's rising stars, seemed to be coasting towards a comfortable lead at the Sarawak Golf Club before stumbling over his last three holes with one bogey and a double bogey in the RM180,000 (approximately US$60,000) Asian Development Tour event.
"I was doing well, and putting decent. But in the last three holes, I didn't quite do it. It was a bad finish," said Choo, who compiled a three-day total of one-under-par 215.
"The greens are tough to get close to as they are firm and quick. They are really challenging and you really need to be patient out there which I was today [Saturday]. I'm quite happy despite the finish," added Choo.
With one round to go, Choo is hopeful he can secure his maiden title on the ADT which rewards the top-three finishers on the final Order of Merit with Asian Tour cards for the 2013 season.
"I'm happy with the way I'm playing in the last few weeks. I've played well in a couple of ADT events as I've been working really hard at my game. It seems to be paying off. I'm confident about tomorrow [Sunday] and hopefully, I can continue to play well and the putts will drop," said Choo.
Ababa shot a solid round of 70, thanks to four birdies against two bogeys, to stay in the title hunt.
"I hit it good on the front nine. I'm really happy. My birdies were from between five to 10 feet. This golf course is hard as it's long and the greens are tough," said Ababa, who finished third in the Bii Maybank ADT Challenge in Indonesia in July.
"I'm just going to enjoy the day tomorrow [Sunday]. I've won three local events on the Philippine Tour last year. But to do it tomorrow [Sunday], I will need to drive the ball well as you can't make mistakes here," he said.
Hong, who held the overnight lead, posted a 76 after rounds of 71 and 69 while local hope, Akhmal returned with another 73 for a 216 total.
Malaysia's S.Siva Chandhran and Jeremiah Kim signed for a 73 and 74 respectively to share fifth place with England's Peter Richardson (70) and Japan's Mitsuhiko Hashizume (71) on 217 at the ADT event.
The ADT, which was inaugurated in 2010 with five events, will stage a minimum of 12 tournaments this season. From next year, all ADT events will receive Official World Golf Ranking points which is a huge boost for the development of the game in Asia.