Four further pars saw Wiesberger turn in 35 and still five clear, although Fraser had been joined in second by first round leader Victor Dubuisson.
The 22 year old Frenchman had dropped off the leaderboard after a second round 75, but six birdies in eight holes from the fourth put him in position for a sizeable share of the €2,205,000 prize fund.
Ramsay holed a five footer at the 16th to move to 12 under, but the gap was not three for long.
Wiesberger hit a glorious pitch at the par five 15th to eight feet and rolled the putt in to advance to 16 under.
|T5||JIMÉNEZ, Miguel Angel||ESP||18||-10|