Morrissey scored at 6:26 of the first period to give the Jets a 1-0 lead.
"You dream of that one in the driveway, basement and the outdoor rink," said Morrissey, a 21-year-old defenseman who played his 19th NHL game. "To finally be able to get that and see it go in was something special. It's starting to sink in a little bit now that the game's over. During the game it's an exciting moment, but you're back to playing right away."
Nikolaj Ehlers made a pass to Mark Scheifele in the slot. Scheifele turned and passed the puck back to Morrissey, who shot past Crawford. The assist was Scheifele's 21st point of the season.
Thorburn made it 2-0 at 4:41 of the third period. He picked up a pass from Paul Postma on the half wall, turned and shot high past Crawford's blocker. Laine scored at 8:32 of the third off a rebound to make it 3-0.
"I just have to work hard all of the time," Laine said. "I could score on the first two [shots], but I think I played pretty well and created some more chances for my linemates."
Petan scored 11 seconds later to make it 4-0. The rookie missed his first shot attempt on a pass from Marko Dano but was able to get his stick on the second for the goal at 8:43.
Blackhawks forward Vinnie Hinostroza left the game in the first period after a hit from Morrissey. Hinostroza's head hit the boards as he fell. Morrissey was given a two-minute minor for charging.
"I think he's going to be all right," Blackhawks coach Joel Quenneville said. "We'll know more tomorrow."