Christiaan Bezuidenhout carded the lowest 36-score in tournament history as he took a two-shot into the weekend at Made in Denmark.
Following on from an opening round of 6 under, the South African shot a 7-under-par-65 to move to 13 under overall. The 24-year-old, who is yet to win on the European Tour, dropped his only shot of the day at the 8th and made five of his eight birdies on the back nine.
Englishmen Lee Westwood and Jonathan Thomson are in a tie for second place at 11 under. Thompson led overnight following a career-best opening round of 8 under, and birdied his final hole of the day to card a 3-under-par-69.
Ryder Cup vice-captain Westwood shot a round of 7 under to keep up with Bezuidenhout's pace. The 45-year-old hasn't won on the European Tour this season but didn't drop a shot during his round.
In the race for the the final automatic qualification spot for September's Ryder Cup, home favourite Thorbjorn Olesen shot a round of 3 under to make the cut.
Olesen can confirm his place on Thomas Bjorn's team with a win at Silkeborg Golf Club but was in danger of missing the weekend after an opening round of 1 over.
The other two hopefuls for the final eighth and final automatic spot, Englishmen Eddie Pepperell and Matthew Fitzpatrick, remain in contention following rounds in the red.
Both players need to win the tournament to clinch the spot, while hoping Olesen finishes outside the top 20. Pepperell is currently 5 under overall in a tie for 30th while Fitzpatrick is a shot further back in a tie for 37th.