He told Sky Sport Italia: "I think the game was practically closed. We were in control in every way, even in the second half and had some more great chances to add to our tally.
"Then something strange and unthinkable happened. We lost a match that we had been dominating. How do we explain it? An explanation would be easy, in 10 minutes we destroyed all the hard work, both during and before the game. We managed to allow Fiorentina back into it and concede odd goals.
"This is football. We have to take these 10 nightmare minutes and learn from them. I continue to say this year will be very, very difficult. There are huge regrets."
A first defeat of the season sees Juventus lose ground on league leaders Roma and go five points behind the Giallorossi in third place.