The summer signing from Norwich City struck late for the 3-2 win.
He told the Athletic: “It showed what made me come to Marseille. It screams passion and love of football and it echoes my idea of the Beautiful Game.
"The reaction of the fans, the staff, that’s why I came here. I didn’t know how to celebrate when I scored, it was all done 'instinctively.
"I’m a man who likes challenges and it’s a different experience, but I’m looking forward to making my mark on another part of the world. It’s a higher level than the Championship, there are fewer games so more time to prepare.
"It’s more structured and the level is higher. It’s a good way to gauge myself. And Roberto De Zerbi taught me to keep going no matter what. It doesn’t matter if it goes in your favour or against you, you have to have the same mentality and try to improve.”