CHICAGO -- In the times this season when the Chicago Bulls have struggled most, coach Fred Hoiberg has bemoaned his young team's tendency to drop its head when trouble hits.

So when the Bulls trailed by nine points late in the fourth quarter on Monday, Hoiberg saw chins again begin to drop. Hoiberg knew if the Bulls' win streak was to continue, something had to change immediately.

Did they ever.

Nikola Mirotic and Kris Dunn each scored 22 points as the Bulls rallied down the stretch for their sixth straight win, 117-115, over the Philadelphia 76ers at the United Center.

Chicago (9-20) also got 20 points from Justin Holiday, 12 from Bobby Portis and 10 apiece from Denzel Valentine and Lauri Markkanen. Mirotic grabbed 13 rebounds, and Portis pulled down 10.

But while Mirotic has sparked Chicago's turnaround during its winning streak, the key in the Bulls' latest victory was how everything came together at just the right time.

"I told them in the huddle that our body language (stunk) -- it was like we were down 20 and it was a two-possession game," Hoiberg said. "Our guys went out there and they rallied."

The 76ers used a 13-2 run to build a 107-99 lead with under four minutes to play. But Chicago, which connected on 13 3-point field goals, rebounded with 11 straight points and took a 110-107 lead on a Mirotic 3-point play with 2:08 remaining.

Mirotic, who has only played this season in each of the last six games, put his emotions on display after being fouled, understanding that the Bulls were on the verge of continuing their winning ways.

"When I'm out there, I'm just trying to make it simple," Mirotic said. "But I'm playing with a lot of confidence right now. For a long time, I wasn't having fun playing basketball -- a long, long time."

A six-game win streak has changed that.

A pair of Dunn jumpers extended the Bulls' lead to 114-109 with 1:05 remaining before the 76ers got to within 117-115 on a Saric 3-pointer with 39 seconds remaining. But the 76ers -- who have lost five of their lost six games -- couldn't get any closer as the Bulls extended their win streak.

"(The late rally) was just huge for us," Mirotic said. "Once again, we found a way to win our game. We never gave up.

"It's all about keep winning."

Led by Mirotic, who sparked Chicago's 49-point bench effort, the Bulls followed suit, especially when it mattered most.

Dario Saric led Philadelphia (14-15) with 27 points, Ben Simmons scored 19 and Richaun Holmes added 14. J.J. Redick scored 12 points for the 76ers, who also got 11 from T.J. McConnell and 10 apiece from Robert Covington and Jerryd Bayless. Simmons also contributed 11 rebounds and nine assists.

The 76ers played without center Joel Embiid, but still had their chances to put the Bulls away late in the fourth quarter. But Philadelphia couldn't match Chicago's intensity in the final minutes and allowed the late lead to vanish.

"We were breaking down on defense a little bit -- we've just got to be more solid," Covington said. "We've had too many times where we've gotten leads late in the game and we've given them up and so we've just got to learn to finish. We've got to get back to what got us that lead."

The Bulls led by as many as 12 points in the third quarter. But after the 76ers went on their run to take the lead in the fourth quarter, Chicago -- which now hasn't lost since snapping a 10-game losing skid on Dec. 8 -- continues to play like a team well beyond its experience level.

"It's all about going out there and playing the right way," Hoiberg said. "But it's still about taking positive steps and our team has done that here these last couple of weeks."

NOTES: Philadelphia C Joel Embiid did not play Monday, continuing the habit of not playing in back-to-back games. Embiid's availability for the Tuesday game against Sacramento had not been determined. Embiid has yet to play against Chicago in his career. Amir Johnson started for Embiid and scored four points. ... Philadelphia F/C Trevor Booker did not play after spraining his left ankle Friday during the third quarter of a triple-overtime loss to Oklahoma City. Booker will also be sidelined Tuesday and is expected to be re-evaluated later this week. ... Bulls F Lauri Markkanen returned after missing three consecutive games due to back spasms. Markkanen was not on a minutes restriction, but coach Fred Hoiberg said he would be "very careful" with Markkanen. ... F Nikola Mirotic, who had been starting in Markkanen's place, returned to his reserve role.