"We had no excuse," Dallas captain Jamie Benn said. "We had the day off yesterday, they played a back-to-back, and there is no excuse and that's why it's disappointing."
Kadri scored to put Toronto ahead 1-0 at 15:50 of the first period. A turnover by Stars forward Mattias Janmark at the Maple Leafs blue line created the chance, and Kadri scored off a pass from Mitchell Marner.
"I knew it was coming the whole way. That's [Marner's] tendency," Kadri said. "He's a passer, but he can also score. He's always got the puck in ready-to-shoot position, but chances are he's going to be looking for you. Playing with him, the only adjustment I've made is just try to have that shooter mentality and get open, and he's going to hit you."
Hyman scored on the rebound of a William Nylander shot at 1:55 of the second period to make it 2-0.
With the Maple Leafs on the power play, Kadri made it 3-0 at 9:29 of the second when his centering pass deflected in off Janmark's stick.