Barton capped a career-high 37 points with a driving layup with 3.2 seconds left and the Nuggets overcame the loss of Nikola Jokic to beat the Chicago Bulls 111-110 on Thursday night.
Gary Harris added 21 points, and Kenneth Faried had 14 points and 13 rebounds for Denver, which lost another big man to injury when Jokic was hurt.
He joins Paul Millsap (wrist surgery) and Wilson Chandler (back injury) on the sidelines.
"We were already without Paul and Wilson, Joke goes down, it was like, Man, we just can't lose this game," Barton said. "I just wanted to step it up. It was definitely one of my biggest games here."
Jokic went down with 44 seconds left in the second quarter when he drove to the basket and stepped on Jerian Grant's foot. Jokic hit two free throws before heading to the locker room with an obvious limp. He didn't return in the second half.
Coach Michael Malone said after the game that Jokic would get treatment and his status for Saturday's game is unknown
Lauri Markanen and Robin Lopez had 20 points each for Chicago, and Kris Dunn added 19. The Bulls have lost seven straight to finish 2-13 in November and drop to 3-17 overall.
The Bulls, who led for most of the game, took advantage of Jokic's absence and led 108-105 in the final minute. Barton was fouled on a 3-point attempt and hit all three free throws to tie it, then made 1 of 2 to give Denver a one-point lead with 20 seconds left.
Dunn gave Chicago the lead with a layup with 9.6 seconds left, and it came down to Barton with the ball.
"I dreamed of those moments when I was young, having the ball in my hands at crunch time and delivering," Barton said. "I'm just thankful I could do that tonight."
He brought the ball up, put a move on Justin Holiday and drove to the basket and hit the reverse layup after the ball hung on the rim.
The Bulls missed an opportunity to get a rare road win.
"I didn't do my job and I let my teammates down," Holiday said. "I just didn't do what I was supposed to do in that situation, that's pretty much it. I am very disappointed. We have that game in the bag. It just hurts that I let my teammates down."
Chicago led 68-62 at halftime but Denver rallied to briefly take the lead in the third quarter. Grant hit a 3-pointer at the end of the third to put the Bulls ahead 92-91.
"We took a step in the right direction tonight and we went out there and competed for 48 minutes," Bulls coach Fred Hoiberg said. "I thought we really had a competitive edge to our team. It's hard to get over big emotional wins and it's tough to get over devastating losses."
Bulls: F Nikola Mirotic has increased his practice load and is close to returning. "He's really in training camp mode," Hoiberg said. "He's had a lot of individual work but nothing simulates that playing up and down, 5-on-5 type action. Mirotic has been out since a preseason altercation with teammate Bobby Portis left him with several broken bones in his face as well as a concussion. ... Zach LaVine (left ACL tear) will have a full practice Friday after going through individual drills Thursday.
Nuggets: Chandler was out for the second straight game with low back soreness. Juancho Hernangomez again got the start in his place. ... Richard Jefferson played a season-high 12 minutes.
When Jokic tried to walk to the locker room after getting hurt, Jefferson ran over and stopped him. The 16-year veteran told the 22-year-old center he needed to take his foul shots before leaving.
"It was chaotic. It was a timeout and he was saying he was done," Jefferson said. "I was like, Dude, if don't go and shoot the free throws, one, the other team gets to pick who shoots them and two, if you go back in the half and you start feeling a little better you can't come back."
Bulls: Host Sacramento on Friday night.
Nuggets: Host the Los Angeles Lakers on Saturday night in Lonzo Ball's first game at Pepsi Center.
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Barton wins game with reverse layup
Nuggets one point behind, and less than 10 seconds on the clock, Will Barton drives in for a game-winning layup.