Australia's Michael Matthews won the uphill sprint to the finish, while Belgium's Thomas De Gendt extended his overall lead in the race.
Froome was taking part in the week-long race in support of his 22-year-old Team Sky team mate Egan Bernal, the recent Paris-Nice winner.
It was unclear whether Froome had suffered any more serious injuries in the crash.
"Froomey crashed just a couple of kilometres before we passed the finish line for the first time," said sports director Nicolas Portal.
"He still doesn't really know what happened, but it was a tricky corner, which had a few roadworks on the right and was also quite bumpy.
"Someone hit him and he slid and crashed. By the time he changed bike and got going, the bunch was going too fast and there was no chance to come back. He is here to support Egan this week but it is a shame it happened."
(Reporting by Julien Pretot; Editing by Toby Davis and Hugh Lawson)
