ATZENBRUGG, June 6, 2014 (AFP) - Lundberg, targeting a first European Tour title in six years, had shared the overnight lead with England's Adam Gee, who carded a 73 to slip to sixth, five shots off the pace.
Lee Slattery is lying second, one shot off the top, with Fabrizio Zanotti a further shot away in third.
Lundberg, targeting his third title, said: "I hit a lot of good shots early on and managed to make some putts, so that got my confidence up.
"I've been doing some great work with my new coach, Neil Jordan, over the last few weeks, and my game is feeling a lot more solid as a result. So whilst I didn't maybe expect to play this well here, it's not a complete shock to me either."
The 40-year-old's previous wins came in the Russian Open in 2005 and 2008 but he hasn't had a top ten finish in nearly two years.
Slattery carded an eagle, five birdies and one bogey in his impressive 66.
"It was great," said Slattery, whose only European Tour win came in Spain three years ago.
"I got off to a decent start again today, and I was off and running. I made some good up and downs at important times, which kept the momentum going.
"It's a tricky course, there are potential disasters on every hole so you definitely can't afford to get ahead of yourself.
"It's quite old school golf where you've got to control your ball and put it in the right places. That suits me, so I'm enjoying it."
The best recovery came from Australian Brett Rumford, who played his first four holes in five over par but the remaining 14 in seven under to return a second round of 70 and finish one under par.
Leading second round scores in the EPGA Austrian Open in Atzenbrugg on Friday (par 72, GBR & IRL unless staed):
135 - Mikael Lundberg (SWE) 67 68
136 - Lee Slattery 70 66
137 - Fabrizio Zanotti (PAR) 69 68
138 - Sihwan Kim (NOR) 70 68
139 - Joost Luiten (NED) 72 67, Rhys Davies 68 71
140 - Adam Gee 67 73, Berry Henson (USA) 68 72
141 - Alex Haindl (RSA) 72 69, Richard Finch 68 73, Matthew Baldwin 68 73, Bernd Wiesberger (AUT) 71 70, Simon Wakefield 70 71
142 - Eduardo De La Riva (ESP) 73 69, Phillip Archer 69 73, Mikko Korhonen (FIN) 75 67, Thomas Levet (FRA) 69 73
143 - Jordan L Smith 71 72, James Kingston (RSA) 72 71, Daniel Im (USA) 70 73, Garrick Porteous 74 69, James Morrison 73 70, Florian Fritsch (GER) 74 69, Brett Rumford (AUS) 73 70, Anthony Wall 70 73, Stephen Dodd 70 73, Andrew Marshall 72 71, Victor Riu (FRA) 69 74, Florian Praegant (AUT) 70 73, Ruaidhri McGee 73 70, Ross McGowan 69 74