Napoli came from behind to win, with Ramus Hojlund scoring the winning goal.
Del Piero commended de Bruyne for taking charge when needed, saying: "When a player doesn't score or provide an assist, people start to question their performance.
However, de Bruyne has been impressive, and his experience and motivation are evident, even as he joins a new team that has recently won a championship.
Del Piero believes de Bruyne is an exceptional player, and his skills and work ethic are still on full display.