And for a team in hot pursuit of an Eastern Conference playoff spot, Mirotic may be heating up at precisely the right time.
Mirotic, who was 6 of 11 from 3-point range, sparked the Bulls from long distance. Chicago finished 12 of 25 from beyond the arc, hitting at least 10 3-point field goals for the fifth straight game.
Mirotic was a big reason why.
"I feel it is my time to make things right," said Mirotic, who was 9 of 14 from the field. "I just want to finish strong at the end of the season and help us get into the playoffs."
A second-half turnaround kept moving the Bulls in the right direction.
Chicago erased a nine-point halftime lead and then held off a late Cleveland charge as Mirotic connected on a pair of free throws with 35 seconds remaining after the Cavaliers drew to within 95-90 on a Tristan Thompson basket.
The Bulls, who got 12 points from Denzel Valentine and 10 points and 11 rebounds from Robin Lopez, overcame a woeful second-quarter shooting performance and used an 11-3 run to close out the third quarter. Chicago kept surging in the fourth quarter when Butler scored 10 points and Rajon Rondo, who had 15 assists, paced the Bulls to the lead before Mirotic's late free throws allowed Chicago to continue its season-long dominance over the Cavaliers.
"We catch Cleveland on bad nights, I guess -- don't know," Butler said. "But we want to continue to win these games. We know where winning can place us and what it can do for us moving forward."
While the Bulls took another step closer to the playoffs, the Cavaliers continued to slide, losing their third straight game and their fourth in the past five games.
Cleveland (47-27) fell a half-game behind Boston (48-27) in the race for the top seed in the Eastern Conference playoffs. The Washington Wizards (46-29) are 1/2 games behind the Cavaliers.
James had 26 points, 10 rebounds and eight assists, and Kyrie Irving finished with 20 points for the Cavaliers. Thompson finished with 15 points, and J.R. Smith had 12. And despite leading by 11 points, Cleveland had no answer for Mirotic and couldn't catch the Bulls down the stretch.
"We're just in a bad spot right now," James said. "I'm not disappointed in the effort. (We're) just in a bad spot and we need it figure it out."
James ended the game with 28,599 career points, three ahead of O'Neal.
The Cavaliers struggled to defend Mirotic, especially in the third quarter when he connected on 3 of 5 3-point attempts as the Bulls outscored Cleveland by 16 points. His effort during that stretch along with the first quarter, when Mirotic scored 13 quick points, not only frustrated the Cavaliers, but energized the Bulls.
"That's how Niko is," Butler said. "When he's making shots, he's making everybody's job easier and he's making (the job) of whoever is guarding him hard. We want him to play like that and be aggressive."
Said James: "We gave them too many good looks. (They) got in transition and got too many good looks."
For Mirotic, who not that long ago was out of the Bulls rotation as he struggled to find his range, his recent performances have turned things around. Mirotic has scored 28 points in three of his last four games as Chicago continues to push for the postseason.
Now, he -- and the Bulls -- are hoping to keep it going when it matters most.
"We have a chance to be in the playoffs," Mirotic said. "Hopefully, we will make it."
NOTES: Cavaliers F Kyle Korver missed his second straight game with left knee soreness and is also expected to miss Cleveland's game Friday against Philadelphia. ... Cleveland F Richard Jefferson missed Thursday's game due to left knee tendinitis. Jefferson did not practice Wednesday. ... Cleveland G Iman Shumpert returned after missing the last two games with right knee soreness. ... Bulls G Dwyane Wade (sprained, fractured elbow) participated in pregame shooting drills before the game, and he hopes to return should the Bulls reach the Eastern Conference playoffs. Wade hasn't played since March 15. On Wednesday, Hoiberg called Wade's rehabilitation a "work in progress" and told reporters that Wade experiences soreness and stiffness after he works out but that team officials want him out "testing" the elbow. ... C Cristiano Felicio was available for the Bulls after missing three games due to lower back stiffness, but he did not play.