Rasmus Kupari and Adrian Kempe scored for the Kings (1-5-1), who are 0-5-1 in their past six games. Jonathan Quick allowed three goals on 31 shots.
"We're finding ways to lose games right now, which is a coach's cliche, but that's a fact," Kings coach Todd McLellan said. "We're a goal short every night and we're finding a way to be a goal short, so we've got to polish things up."
Dubois tipped Connor's pass in after getting behind Kings center Anze Kopitar and defenseman Olli Maatta to put the Jets ahead 3-2 at 7:35 of the third period.
"Luc is hot right now, get him the puck," Connor said. "And he's just one of those big bodies going to the net. He's got that straight line speed and he's tough to cover."
Dubois has nine points (six goals, three assists) during an NHL career-best six-game point streak.
"One thing that I've been working on is just trying to be consistent," Dubois said. "It's a long season, and I've gone stretches without scoring for many games and I've gone stretches scoring and feeling good for a long period of time, so it's just about finding what you do right and just keep going with it. I just want to be consistent and consistently help the team win, and right now the puck's going in, but I want to be helpful defensively, helpful offensively without the puck, with the puck, everything."
Andrew Copp scored on the power play to tie the game 2-2 at 2:07 of the third period. Copp got positioning in the slot to redirect Connor's pass in.