CHONBURI, Thailand, Dec 8, 2012 (AFP) - Schwartzel, who has not tasted victory since the US Masters in 2011, kept the chasing pack at arms-length with a controlled four under 68 for the day giving him 18 under overall at the Asian Tour event.
While it was not as polished as his flawless matching 65s in the opening two rounds, the South African enters Sunday confident of a pillar-to-post victory and the chance to avenge his second place last year to Lee Westwood.
"I feel comfortable, I won't change (my approach) I will just keep playing and see where it leads to... it's a game of patience and if it's my time, it's my time," said Schwartzel, who was runner-up at the event last year.
Sweden's Daniel Chopra is in second at 13 under overall, after a three under 69, while home favourite Thitiphun Chuayprakong gamely notched five birdies to offset four bogeys and goes into the final day finish 12 under.
The 20-year old needs to maintain his form while hoping for a wobble from Schwartzel and Chopra who sits a shot ahead of him.
"There's a bit of pressure playing with Charl Schwartzel, but today I coped with it," a smiling Thitiphun told reporters. "I was a little nervous at the first tee, but after I hit the ball the nerves were all gone."
Australian Scott Hend, who is 12th on the Asian Tour's Order of Merit, is poised in fourth on nine-under for any wobbles by the leading trio.
Chopra, who has won twice on the PGA tour in a chequered career, vowed to push Schwartzel all the way on Sunday.
"My goal is to go out there and make it uncomfortable for Charl. Nobody wants to see him run away with it. I want to do my absolute best to make it close down the stretch," he said.
But it appears to be Schwartzel's title to lose after three days of hitting the fairways and precision putting which has countered his rare mistakes and kept the pressure firmly on his rivals.
"I've made good saves at the right time. They keep the momentum going... which is sometimes better than a birdie," the rangy South African said.
The third round brought him three birdies and an eagle at the 11th which made amends for his first bogey of the tournament on the ninth.
Behind the leading group the big names finally made a charge, with Ryder Cup star Sergio Garcia scoring a 68 to leave him ten under for the tournament and Belgian Nicolas Colsaerts finally finding some form to end the day seven under overall.
But it appears to be too late for both of them with a yawning gap to Schwartzel, something Garcia appeared resigned to after his round saying "Charl seems to be flying out there".
Defending champion Lee Westwood repeated his two under 70 of the first day, leaving him at seven under where he was joined by Masters champion Bubba Watson and Japan's Ryo Ishikawa, who both endured patchy rounds.
"It was not very good. I got hot today and didn't putt and hit good shots," the affable American said. "I bogeyed the last which really hurt. If he (Schwartzel) is playing the way he is playing then it might be impossible (to win)."
Scores after the third round of the Asian Tour Thailand Golf Championship at the par-72 Amata Spring Country Club on Saturday:
198 - Charl Schwartzel (RSA) 65-65-68
203 - Daniel Chopra (SWE) 67-67-69
204 - Thitiphun Chuayprakong (THA) 66-67-71
206 - Sergio Garcia (ESP) 69-69-68
207 - Scott Hend (AUS) 70-68-69
208 - Masanori Kobayashi (JPN) 68-67-73
209 - Hyun-bin Park (KOR) 68-74-67, Bubba Watson (USA) 68-70-71, Nicolas Colsaerts (BEL) 72-67-70, Ryo Ishikawa (JPN) 70-66-73, Lee Westwood (ENG) 70-69-70, Anirban Lahiri (IND) 70-69-70, Thaworn Wiratchant (THA) 69-70-70, Jbe Kruger (RSA) 69-70-70
210 - Hunter Mahan (USA) 71-69-70, Chapchai Nirat (THA) 70-73-67, Simon Dyson (ENG) 72-71-67