Wiesberger posted a two-day total of seven-under-par 137 to take a slender shot lead over 2010 Ballantine's Championship winner Marcus Fraser of Australia who returned with a 67 at the Blackstone Golf Club.
Sweden's Oscar Floren is a further shot back in third place on 139 while Spain's Miguel Angel Jimenez is tied for fourth alongside England's Anthony Wall and Chile's Felipe Aguilar on 140.
England's Ian Poulter is among eight players who are five shots back of Wiesberger in tied-11th.
Wiesberger, who opened with a 72 under blustery conditions in the first round, took advantage of the benign conditions in the morning to mark his card with seven birdies in a blemish-free round.
"Yesterday was a grinding day for everybody. It was windy day and you couldn't really tell where the wind was coming from. It was gusty and a tough day," said Wiesberger, who is targeting his maiden victory on Tour this week.
"I really got to the stage where it kind of worked. Today I couldn't really do anything wrong. I felt like everything was going in the right direction," added the Austrian.
Fraser is hoping to repeat his 2010 winning performance after a round of 67 which could have been lower if not for his putting woes.
"I gave myself plenty of chances out there, and it's just a shame that I missed a few putts on the last probably six or seven holes, which was a bit frustrating," said Fraser.
"But overall I'm, very happy and pleased with the way it's going at the moment," added Fraser, who marked his card with seven birdies and two bogeys.
Fraser, who has a well-stocked cellar of Ballantine's, is delighted that his love affair with the brand is still going strong.
"Overall, I'm very happy and pleased with the way it's going at the moment. It's obviously just the alcohol and I can't really survive without it," said a jubilant Fraser.
"They looked after me after I won, and I've developed quite a taste for it now. It's a pretty impressive product, so I'm getting quite accustomed to it," added the Australian.
Reigning Open champion Darren Clarke of Northern Ireland will not be among the 73 players featuring in the weekend rounds after he missed the cut which was set at four-over.