Colton extended the lead to 2-0 at 11:37 off a pass from Nicholas Paul. After Stamkos scored, Kucherov made it 4-0 with a power-play goal at 15:07. Kucherov has 601 points (241 goals, 360 assists) in 556 games.
"I really like a lot of the things we did, but don't read too much into it, it's just one game," Lightning coach Jon Cooper said. "A lot of things went our way, we earned a lot of our own breaks, but it's just one game."
Ondrej Palat pushed the lead to 5-0 at 1:12 of the third period with a redirection of a shot from Mikhail Sergachev. Killorn's second goal came off a power play and made it 6-0 at 4:33.
Mikheyev made it 6-1 with a power-play goal at 7:45.
"There are a couple of things we're disappointed in, obviously in the way we played, just not helping out our goaltender," Maple Leafs captain John Tavares said. "Second, it's a good lesson for us going forward to understand just the way we need to play. Obviously against a team like this they don't need a whole lot and the game changed really quickly there in the second period."
Colton's second goal came off a power play at 8:50 to make it 7-1, and Pat Maroon scored his 10th goal of the season at 14:11 for the 8-1 final.
NOTES: Maple Leafs center Auston Matthews missed his third game with an undisclosed injury. Keefe said he is really close to returning. ... Lightning forward Brayden Point was a late scratch with a lower-body injury. He is day to day. ... Kucherov has eight points (five goals, three assists) during a four-game point streak. ... Colton has five goals in his past four games.