More amazingly, Utah is only a half-game out of fourth, which carries a home-court advantage in the first round of the playoffs.
"We've been working our way back in it," said coach Tyrone Corbin. " … [But] it's going to be a dogfight the rest of the way. We can't afford to relax now that we're back in the picture."
Playing their third game in four nights and back-to-back after an emotional 103-102 win at Sacramento on Thursday, the Jazz improved to 19-6 at EnergySolutions Arena by crushing Denver.
"It was a tremendous gut-out victory for us," Corbin said. " … It took us a little while to get going, but I thought once we got going we did a great job controlling the tempo."
The Jazz used a 20-7 run at the end of the second quarter to grab a tenuous 63-55 lead.
But Utah opened the second half by scoring on its first seven possessions, which triggered a 28-9 run to make it 91-64.
Gordon Hayward scored nine of his 15 points in the decisive third quarter, while Paul Millsap and Jefferson each added eight.
"We just got aggressive got out and ran," Millsap said. "We made shots and didn't turn the ball over."
Corbin thought the Jazz got into a "rat-race kind of game" with high-octane Denver in the first half and settled for too many jump shots.
During what turned out to be a furious 48-16 run over a 15-minute span, however, Utah aggressively went to the basket.
"You want to attack against these guys," said Corbin. "They want you to get into a jump-shooting contest with them and that's not who we are."
In all, the Jazz had seven players score at least 12 points.
Rookie Alec Burks joined Hayward with 15 while Millsap ended up with 14 despite early foul trouble.
Al Harrington led the Nuggets with 20 points, but Denver shot only 43 percent in the second half. At 26-22, Utah is tied with Denver and Houston for seventh place in the West. The Jazz trail Dallas, Memphis and the L.A. Clippers by a half-game.
"The guys have stayed together," Corbin said. "We've stayed the course. We talk about it all the time the NBA is a long season. You're going to have some peaks and valleys. But you have to make sure you stay focused on the things you need to get better at. And we've done that."
Before the game, Denver coach George Karl addressed Utah's improvement since the All-Star break.
Specifically, he mentioned the play of Derrick Favors, Enes Kanter, Burks and Hayward.
"I like how their team is coming together," Karl said. "Their bench has gotten strong. The big kids are playing great. The Burks kid is developing. …
"I love their wings. Their wings are playing at a high level. The Hayward kid is [getting] better every week."
Although the Nuggets scored 102 points against Utah, including 55 in the first half, Karl also credited the Jazz's return to playoff contention to their defense.
R Al Jefferson scores 23 points to lead the Jazz to a 121-102 victory over Denver.
• Utah moves into a tie for seventh place in the Western Conference playoff race.
• The win was the Jazz's sixth straight and 11th in the last 15 games.