Having fired a seven-under-par 65 in the final round for a total of 276, the 40-year-old Swede held his nerve in the playoff to hole a 40-foot birdie putt on the par-three 18th against 2012 champion Wiesberger.
Runner-up and local favourite Wiesberger (69) was hoping victory in Atzenbrugg would confirm his place in next week's US Open Championship at Pinehurst but he will now rely on results going his way at the FedEx St.Jude Classic in Memphis.
"Today just started off really well on the first couple of holes," Lundberg told reporters afterwards.
"I made some really nice putts and changed the whole attitude. And then, what can I say, I didn't hit a great shot on the last (first play-off hole) and Bernd hit a fantastic shot but that's golf and I made a fantastic putt.
"Luckily I had almost the same putt on the 72nd hole so I got the line a little bit but to hole that one was just fantastic."
Joost Luiten, who is aiming to become the first Dutchman to play in the Ryder Cup later this year, squandered a two shot lead going into the final round as he carded a level par 72 to finish third.
- Sports & Recreation