Healy attacked from an eight-man breakaway, which included Van der Poel, with over 40km remaining on the 201.5km ride from Bayeux to Vire Normandie, and pulled away to reach the finish line well ahead of American Quinn Simmons with Australian Michael Storer third.
Van der Poel, who lost the overall lead to Pogacar after Wednesday's individual time trial, was unable to keep pace with the breakaway but moved back to the top of the general classification with a gap of one second over the Slovenian champion.