Austria's Bernd Wiesberger set the clubhouse target in the weather-affected Porsche European Open, while Michael Hoey also completed his round to lie four shots off the pace.
After the start of play was delayed by three hours and 25 minutes due to fog, Wiesberger carded a superb eight-under-par 63 to claim a two-shot lead over Italy's Renato Paratore, with half the field unable to complete their rounds before darkness fell.
Starting on the back nine, Antrim man Hoey carded birdies on 10, 16 and 17 before making an eagle on the first. He followed that up with his only bogey of the round on the second for a 67 to lie tied in eighth place on four under.
Of the other Irish involved, Padraig Harrington was the only other to finish his round - he battle through a wrist injury to mix four bogeys with four birdies for level par, while Ruaidhri McGee is two under after nine holes and Paul Dunne one under thru six
Wiesberger held a share of the lead in the same event 12 months ago after an opening 64, but then carded a second round of 76 to amazingly miss the halfway cut.
"I started 64 last year and desperately wanted to make that (birdie) putt on the last to not make too many memories come up," admitted the 30-year-old, whose second place in the KLM Open a fortnight ago was only his third top-10 finish of the season.
"But tomorrow I'm thinking more about what happened today and am going to keep pushing and try to play the game I've played today.
"What happened a year ago was funny at the time, or not funny right after the round but it was a weird week and I pretty much know I'm not going to repeat that tomorrow."
Starting on the back nine at Golf Resort Bad Griesbach, Wiesberger birdied five of his first eight holes to race to the turn in 31, only to drive out of bounds on the first to run up a double-bogey six.
The three-time European Tour winner responded with birdies on the next two holes and also finished his round in style with an eagle on the eighth and a closing birdie to avoid another 64.
Paratore also had a double bogey on his card, at the fifth, in his 65, but posted six birdies and an eagle to finish a shot ahead of Lucas Bjerregaard, Daniel Im, Michael Jonzon and Steve Webster, with Matthew Southgate also five under after 11 holes.
Ryder Cup team-mates Martin Kaymer and Thomas Pieters were level par and two over respectively after nine holes.
