The Austrian opened with five consecutive birdies in a nine-under round, finishing with three further birdies to move clear of the chasing Alejandro Canizares.
Wiesberger is without a European Tour victory since claiming the Lyoness Open title three years ago, but the world No 48 is not yet thinking about adding a first title of the year just yet.
???I don???t want to get fooled by the position,??? the Austrian said. ???There are a lot of good scores out there.
???You could see everyone shooting well under-par and moving quite drastically on the leaderboard, so I???m not really looking for pars but trying to make some early birdies.
???If I get out of the gates as quickly as I did today, then I???m in a good position to hopefully have a good Sunday.???
Midway joint-leader Lee Westwood will head into the final round three shots off the pace after a three-under third round 69.
The world No 30 carded back-to-back birdies from the final two holes to move tied-third with Paul Waring, but feels fortunate to still be in contention of retaining the title he won by seven shots last year.??
???It was nice to birdie the last two holes and finish with a bit of momentum,” Westwood said. “The way I played it could have been a lot worse and I could have been a lot further off the lead.??
???I couldn???t feel my hip action today and really struggled especially early on, but I only made one bogey and made some crucial birdies on 17 and 18, which if I don???t make I???m probably five behind.
???I could have easily shot over-par today so I???m very pleased to have shot 69.???