Gavi had been missing for six months as he recovered from an ACL injury.
Advertisement
Advertisement
The Spain midfielder was introduced on 82 minutes and given a standing ovation by the Nou Camp crowd.
The 5-2 win marked Gavi's first appearance in 205 Barca games.
He later posted to social media: "It's been very tough, even more so than last time. It's been the most painful process, and the day-to-day has been harder.
"The feeling at Camp Nou, with my people, with the fans, is unique, and I'm very happy.
"Hansi Flick has always been there for me, like a father. I'm very grateful to him. He's always believed in me."