SEOUL, April 28, 2012 (AFP) - The 25-year-old Austrian fired a second successive seven-under 65 to take a stranglehold on the $2.9 million tournament at Blackstone Golf Club, Icheon, near Seoul, South Korea.
His three-round total of 202, 14-under-par, stretched his overnight lead to five shots over Australia's Marcus Fraser, who struggled to cling on to his playing partner's coat tails with a 69.
A shot further back were England's Oliver Fisher (67) and Chile's Felipe Aguilar who carded a four-under 68.
"I think that's what you call a great day at the office," said Wiesberger.
"It was fun out there. I enjoyed myself and made a lot of putts which was the key to another perfect day.
"I don't know if I've ever gone two bogey-free 65s in a row, so it was great."
Ireland's Paul McGinley set a scorching pace in the first group out on Saturday by rolling in birdies at five of his first six holes on his way to a seven-under 65, equalling the best round of the week.
But despite his efforts, which moved him up to fifth on the leaderboard by the end of the day, he was seven adrift of Wiesberger.
In calm, warm conditions perfect for scoring well under magnificently clear blue skies, Wiesberger started steadily, tapping in his first birdie on the fourth and notching another on the sixth to reach the turn in 34, two-under for his round and nine-under for the tournament.
But it was on the back nine that he got hot with the putter, rolling in a succession of birdie putts on all the even-numbered holes 10, 12, 14, 16 and 18 to move to 14-under-par -- six shots clear of the chasing pack.
Wiesberger said it was the birdie on the par-four 10th, which statistically has been the toughest hole all week and one of the three toughest on the European Tour this year playing at an average of 4.5 strokes, that really got him going to come home in just 31 shots on the back nine.
"It kind of jump-started the back nine. It was less windy than the first two rounds and it was a fairly accessible pin today and I had a fairly easy uphill putt, not too much break."
Wiesberger's previous best finish on tour came when he was runner-up to Hennie Otto in the SA Open Championship at Serengeti in November last year.
He has played steadily in 2012, but his only top 10 came in the Johannesburg Open in January, where he finished ninth, four shots behind Branden Grace.
Wiesberger said that his experience back on the second-string European Challenge Tour where he won twice during the last two seasons after losing his Tour card in 2009 should stand him in good stead for the final round on Sunday.
He will be wary though of a chasing pack featuring such European Tour luminaries as Miguel Angel Jimenez, Y.E. Yang, Ian Poulter and Paul Casey.
The Spanish veteran Jimenez, who was runner-up here last year, lies seven shots back after a 69 on Saturday.
Hero of the home fans Yang shot a superb six-under 66 and is on five-under for the tournament on the same mark as England's Poulter who carded a three-under 69.
Fellow Englishman Casey is a shot further away having again failed to find his touch on the greens despite some fine ball-striking in a two-under-par round of 70.
McGinley last tasted success on the European Tour in 2005 but his spectacular round earlier in the day seemed to have given him a chance to end that drought, before Wiesberger matched the Irishman's score and drew away.
Leading third-round scores on Saturday in the European Tour/Asian Tour $2.9 million Ballantine's Championship, at Blackstone Golf Club in Icheon, South Korea: (Par 72)
202 Bernd Wiesberger (AUT) 72-65-65.
207 Marcus Fraser (AUS) 71-67-69
208 Oliver Fisher (ENG) 71-70-67, Felipe Aguilar (CHI) 71-69-68.
209 Paul McGinley (IRL) 71-73-65, Miguel Angel Jimenez (ESP) 72-68-69.
210 Kiradech Aphibarnrat (THA) 76-69-65, Richie Ramsay (SCO) 70-72-68, David Howell (ENG) 73-69-68, Alexander Noren (SWE) 75-66-69.
211 Gregory Havret (FRA) 76-69-66, Y.E. Yang (KOR) 74-71-66, David Oh (USA) 73-70-68, Victor Dubuisson (FRA) 68-75-68, Ian Poulter (ENG) 75-67-69, Thongchai Jaidee (THA) 71-71-69, Anthony Wall (ENG) 73-67-71.
212 Prom Meesawat (THA) 72-72-68, Siddikur Rahman (BAN) 75-69-68, Romain Wattel (FRA) 72-73-67, Soren Kjeldsen (DEN) 74-69-69, Bae Sang-moon (KOR) 75-68-69, Paul Casey (ENG) 70-72-70.
213 Brett Rumford (AUS) 73-70-70, Thaworn Wiratchant (THA) 73-70-70, Ross Fisher (ENG) 71-72-70, George Coetzee 71-71-71, Graeme Storm (ENG) 72-69-72.
214 Mikko Ilonen (FIN) 75-69-70, Shane Lowry (IRL) 74-70-70, Berry Henson (USA) 74-72-68, Richard S. Johnson (SWE) 73-73-68, Jeev Milkha Singh (IND) 72-74-68, Oscar Floren (SWE) 72-67-75.
Selected others:
215 Adam Scott (AUS) 71-76-68.
218 K.T. Kim (KOR) 73-75-70.