The highly-fancied Dane was pictured with blood streaming down his face and right arm after the incident with 18 kilometres remaining.
Four Astana teammates held back to help their GC leader bridge the 25-second gap back to the peloton, successfully making touching distance before the end of the stage.
He was later taken by his team for medical check-ups, but was cleared for Sunday’s second stage.
“A rider crashed in front of me at the moment we were going to the front of the peloton to stay out of trouble, it was impossible to avoid him and so I crashed,” he said.
“It’s not the way you want to start the Tour. I’m happy that there were no fractures, so I’m able to continue the race. We’ll see how it goes tomorrow.”