The Norwegian scored one and set up another in a 3-1 win over the Catalan giants, who arrived as defending champions and having lost a solitary match all season.
Lyon made a magnificent start when Amandine Henry fired a superb 35-yard effort past Barcelona goalkeeper Sandra Panos to give the French side the lead with just six minutes on the clock.
Barca were visibly wilting under the pressure and Hegerberg doubled Lyon’s lead in the 23rd minute when she peeled off her marker to head home from Selma Bacha’s pinpoint cross.
Hegerberg nearly made it three two minutes later but was denied by the legs of Panos, but Catarina Macario did extend Lyon’s lead just past the hour mark after bundling home from a Hegerberg cross.
Barcelona gave themselves a glimmer of hope before the interval when captain Alexia Putellas volleyed home in the 41st minute.
But despite an audacious 50-yard lob from Patri Guijarro which hit the crossbar in the 58th minute, Barcelona were never able to score a second goal that might have made things interesting.
It would have been fitting for Hegerberg to have the final say but her volley crashed off a post in the dying moments.
“We felt a strength from all the team, I think everyone was motivated 200%,” said player of the match Henry.“We had said since the beginning of the season that we wanted to win this trophy back. So we really wanted to make our mark on the field. And I think we did it more through mental strength than physical.”
Additional reporting by PA Sport.