"It's not us getting beat because of our systems," he said. "It's not us getting beat because the other team is better than us. We're beating ourselves. It's the most frustrating part because you know you have the ability to stop it, but it's also reassuring knowing we can fix it."
Lightning coach Jon Cooper challenged Tampa Bay's leaders to address their defense.
"I think there is a little bit of entitlement running through our team right now," Cooper said. "What is a little discouraging is our goaltender, who in my opinion has been our MVP this year, for us to let him down like that … those goals going in at the start of the [first] period were men's-league goals. That's just a noncommitment to play in your own end.
"To win in this League, you have to play in your own end. So there is a group of guys who are going to have to circle the wagons in there, the leaders, and figure this one out because we are just going down a road right now. It's that part of the season right now you just can't let things slide."
The Senators scored the first three goals of the game. Dzingel scored his 12th of the season to make it 1-0 at 4:48 of the first after Stone intercepted a pass by Jake Dotchin deep in the Tampa Bay zone.