Dougie Hamilton scored to end his 26-game goal drought, and Jack Hughes and Brett Pesce each had two assists for the Devils (22-17-2), who have won two straight games in regulation for the first time since winning seven in a row without reaching overtime from Oct. 11-24. Jacob Markstrom made 30 saves.
"Thought it was a pretty clean game," New Jersey coach Sheldon Keefe said. "Not our best game, not a perfect game by any means, but did more than enough to put ourselves in a spot to win. And I thought we managed it well."
Michael Carcone scored, and Karel Vejmelka made 26 saves for the Mammoth (19-20-3), who have lost three of four. They won 7-2 at the New York Islanders on Thursday.
"We don't want any moral victories," Utah coach Andre Tourigny said. "We want to own our results. Obviously, today, it didn't go the way we want. So, it will be important to reflect on it and make sure we arrive with good answers."
Bratt put New Jersey ahead 1-0 at 12:27 of the first period. Pesce missed with a shot, and Bratt collected the puck behind the net before wrapping a backhand around the left post and in off the skate of Utah forward Barrett Hayton.
"We got the type of start we wanted," Bratt said. "Get some good O-zone shifts, get some pucks to the net creating chaos there. And we got some goals out of that. Yeah, we got a good start."