Matthias Schwab withstood inclement conditions to move into a one-shot lead at the halfway mark in the Made in Denmark on Friday.
The Austrian shot a bogey-free five-under 66 on a wet, cold and windy day to hit the front at Himmerland Golf & Spa Resort.
Schwab held a three-shot advantage on eight under at the end of his round, but Alejandro Canizares and Romain Langasque were breathing down his neck on seven under going into the weekend.
Frenchman Langasque also shot a 66 when the rain relented but with winds still high, while Spaniard Canizares signed for a two-under 69.
Schwab made three birdies on the front nine and two after the turn to give himself a great opportunity to claim a maiden European Tour win.
He said: "I'm feeling good. I'm happy about how the day went.
"I'm a little bit happy that it's over too because, especially early, it was very difficult and not much fun to be out there with rain and wind and very cold but, in the end, it turned out to be a good day for me. It was just one shot at a time.
"I think I usually play pretty okay on courses that are tough, I guess that suits me and I guess I'm a good wind player too. I really just want to do my own thing and see what comes out."
Robert MacIntyre, Bernd Wiesberger and Alvaro Quiros are three shots adrift of Schwab on five under.