The immensely popular midfielder made a triumphant return for their match against Tottenham in the Premier League.
Gross came to say goodbye to fans after a summer transfer to Borussia Dortmund.
Asked what he wanted to tell supporters at the Amex, Gross replied: "Thank you for everything.
“You've been unbelievable. I want to thankyou and goodbye. Let's win this game!"
Brighton did have a bad start in the game, going down 2-0, but recovered to win 3-2.