Bernd Wiesberger shot nine birdies and one eagle to lead the European Open by two strokes after a shortened opening day on Thursday.
Play started 3 hours, 25 minutes late because of fog, and some leading contenders did not complete the first round in fading light.
Wiesberger finished with an 8-under 63, notching five birdies on the back nine, where he started. The Austrian, who hasn't missed a cut on the European Tour this season, produced a double bogey on the first, and had another bogey on the fourth, but recovered with an eagle on the eighth.
Renato Paratore of Italy was two shots adrift, with six birdies and an eagle to compensate for a double bogey on the fifth.
Denmark's Lucas Bjerregaard, American Daniel Im, and England's Steve Webster all held the lead before Wiesberger's late charge took him to the top, and they finished the day at 5 under, along with Sweden's Michael Jonzon.
England's Matthew Southgate was also at 5 under through 11 holes.