Del Piero says while PSG have spent a lot of money, it's important that Al-Khelaifi has been an ever-present force at the club.
He explained to Sky Italia: "Everything worked for PSG, I'm not saying it was easy, but even psychologically they handled it like a friendly, like the tenth game of Ligue 1, they had a serenity in their play from the first minute…
"It's something special, here we are still talking about the coach, Luis Enrique. Where everyone else has failed, where everyone hasn't won, he has managed to win, with a change of mentality.
"The owners have put in a lot of money, but the owners are there and present, Luis Enrique has trained the man first and then the player. And it was evident in all the recoveries.
"Were there three Vitinhas on the pitch on the night? All these things were missing over there: we're not talking about a bad day, but about everything going wrong."