Tavares pushed the Toronto lead to 3-1 at 7:07 of the second period when he scored off a William Nylander pass on a 2-on-1, extending his point streak to eight games (five goals, seven assists).
"That's their playoff game," Hellebuyck said. "Now we know what we're going to see in the playoffs if we run into them. We didn't have very good luck; off the stanchion, that's not great. Third one, I lost an edge. That's pretty routine movement for me, and I was right on it. Two game-changing goals, but it is what it is."
Alex Kerfoot scored into an empty net with 1:30 remaining in the third period for the 4-1 final.
Jets forward Mark Scheifele was benched for 16:59 bridging the second and third periods.
"We have some things that we value as a group," Winnipeg coach Paul Maurice said. "Mark's a real competitive guy. Sometimes that gets the best of him I think. We just need to adhere to our core values."
Hellebuyck said of the benching, "It's a message that no one's safe. For me, when you see that, you want to play hard for [Scheifele]. You want to play harder for him and pick him up.
"This is going to be a big character build for us as team. You never know how much adversity you go through, and we seem to keep going through little spurts of adversity. Hopefully we come back from this stronger. We have the character to do that, and it's time for us to learn and prove it."
NOTES: Thornton (41 years and 296 days) became the oldest Maple Leafs player to score a goal, surpassing Allan Stanley (41 years and 252 days), who scored at the Oakland Seals on Nov. 8, 1967. … Marner scored his 100th NHL regular-season goal in his 348th game.