El Bilal Toure scored Stuttgart's winner, with Danilo being sent off for Juve and Perin also saving a penalty for the hosts.
The goalkeeper was named man-of-the-match and later said, "We were a little below par, we didn’t have the energy that we needed to get out of those situations and resolve those problems.
“I know that there are many people who think I chose to stay at Juve because it was comfortable, but the opposite is true.
“It’s tough to keep balanced when not playing often and it requires a lot of extra work to keep physically and psychologically in shape.
“Unfortunately, I cannot enjoy this award because it came along with a defeat.”
Perin added: "They are a very good team, but I am convinced that this defeat will help us to grow. I’ve never seen anyone win without having some failures first and we’ll learn this lesson.”