Lautaro was again involved as his low cross deflected off Federico Ceccherini and into his own net. Gaetano Castrovilli got his second in two games to level the match once again.
Then the game swung in the other direction as Federico Chiesa finished a brilliant Frank Ribery through ball to give Fiorentina the lead.
Inter though fought until the end and got their reward when first Romelu Lukaku opened his account in 2020/21, and D’Ambrosio bagged the winner with one minute left to play.
That means Antonio Conte becomes the first Inter coach to win his first match of the season in two consecutive campaigns since Roberto Mancini.