Kyle Wellwood, Aaron Gagnon and Andrew Ladd all scored in the second period, while Ondrej Pavelec made 29 saves as Winnipeg bested Buffalo, 4-1, at MTS Centre.
Blake Wheeler posted an empty-net tally for the Jets, who have won two in a row to erase the memory of a five-game losing skid.
Winnipeg remained within two points of Southeast-leading Washington, which won at Montreal earlier on Tuesday.
"I think we did a great job in all aspects tonight," said Pavelec. "The defense played great and we got some good goals. This was a good win at a big time for us."
Kevin Porter lit the lamp and Ryan Miller stopped 26 shots for the Sabres, whose three-game win streak came to an end.
"I thought we were okay," said Buffalo head coach Ron Rolston. "There were too many times there, especially in the second, where we gave up too much easy offense. It just wasn't good enough."
Porter pulled the Sabres within 3-1 when his cross-ice pass deflected off a Jets defender and skittered by Pavelec with 4:54 played in the final period.
Pavelec stopped the other 13 Buffalo shots in the final 20 minutes, and Wheeler scored into the vacant Sabres' net with 26 seconds on the clock.
Wellwood broke through at 4:54 of the second period by ripping home an Evander Kane rebound from the slot, then Gagnon doubled the Winnipeg edge just after the midway point of the contest with his first NHL tally.
Ladd capped the Jets' strong middle period on his marker with 22 seconds left before intermission, when he took a Bryan Little feed and moved around Miller atop the crease for the easy tap-in.
Ladd's goal snapped a 13-game drought, dating back to a tally on March 14 against the New York Rangers ... Gagnon played in 29 games for Dallas (2009-11) and Winnipeg (2011-present) without scoring prior to Tuesday ... Both teams are back in action on Thursday, as Winnipeg continues its six-game homestand against Florida and Buffalo returns home to entertain Montreal.