The Jet defenceman stepped into a Patrik Laine feed along the blue line and ripped the puck past Chicago goaltender Corey Crawford 1:36 into the third period.
He got a little bit of help on the play as the puck changed direction when it hit Blackhawk winger Alex DeBrincat's stick and sailed past Crawford.
“Obviously it wasn’t the prettiest goal I’ve ever scored but it was a big one," said Beaulieu. "That was a grinder for us. We knew how important that win was for us, just the points in the standings. It wasn’t our best game, but you’ve got to win those games at important, key times.”
The win snapped a two-game losing skid for Winnipeg, who close out a six-game homestand on Tuesday against Los Angeles.
Mason Appleton had a goal and an assist for the Jets.
Jack Roslovic also scored for Winnipeg.
Connor Hellebuyck made 31 saves for the Jets, who posted their 30th win of the season.
Patrick Kane had a goal and an assist for the Blackhawks, who lost for the fourth time on their five-game road trip.
Ryan Carpenter scored for Chicago.
Corey Crawford stopped 35 shots for the Blackhawks, who dropped to 26-25-8.
Ryan Carpenter got Chicago on the board 15:44 into the first period when he redirected a Patrick Kane backhand from the right corner past Connor Hellebuyck to make it 1-0.
The goal was his 3rd of the season.
Mason Appleton tied the contest 6:38 into the second after the Jet winger redirected a Nathan Beaulieu shot from the point past Corey Crawford to make it 1-1.
The goal was his 4th of the season.
Kyle Connor appeared to have given the Jets the lead at 9:05 when he knocked the puck into the goal when the puck careened off the glass from a Tucker Poolman shot and he batted the disc into the net.
The goal was disallowed and the game remained tied.
Winnipeg took the lead 15:37 into the second when Jack Roslovic redirected a Dimitry Kulikov shot from the point past Crawford to make it 2-1.
The goal was his 12th of the season.
Patrick Kane made it 2-2 with 52 seconds left in the second after a nice setup by Blackhawks captain Jonathan Toews. Toews took control of the disc in his own end and crossed the Jet blueline before working a give-and-go with Dominik Kubalik before dishing to a streaking Kane who was driving the net.
Kane beat Hellebuyck with a low shot to tie the game.
The goal was his 27th of the season.
“It's tough," said Kane. "It stings right now, for sure. Played great in the first again, probably an even period, but given the back-to-back situation it was nice to be up 1-0 and they started taking it to us in the second again. Kind of similar to the last game.”
Nathan Beaulieu gave the Jets the lead 1:36 into the third period, one timing a Patrik Laine feed past Crawford to make it 3-2 Winnipeg that changed direction off of Alex Debrincat's stick and sailed past the Chicago goaltender.
The goal was his 1st of the season.
Jets Head Coach Paul Maurice gave credit to Beaulieu afterward.
“Good for him because he’s done lots of really good things for us and those guys don’t get much of a payoff sometimes. They play hard minutes, normally a lot of penalty-kill time and get some people to the net but good for him, he’s earned it," he said.
Blackhawks Head Coach Jeremy Colliton said his club gave up three goals from point shots and that was the difference in the game.
"I thought overall we played pretty hard. It was a pretty even game. Ultimately I think the difference was you know they scored three goals on point shots and got traffic and give themselves a chance to get a bounce. We had our chances to tie it up but you know it's, I think we need to find a way to generate some of those goals ourselves."
Chicago returns home to host the Rangers on Wednesday while Winnipeg closes out a six-game homestand Tuesday against Los Angeles.
SHOTS-CHICAGO 33 WINNIPEG 38
NOTES-The game had no penalties.