CHICAGO -- It looked like the Boston Celtics eked out a narrow victory against the Chicago Bulls on Thursday night at the United Center.

Instead, the Bulls got a second chance after Jimmy Butler's last-second jumper hit the rim and bounced away as time expired. A touch foul was called on Celtics guard Marcus Smart, 0.9 seconds were put back on the clock and Butler sank two free throws to give the Bulls a 104-103 victory.

"It was a bad call," said Celtics guard Isaiah Thomas, who had 29 points and scored 20-plus points for the 41st straight game to break John Havlicek's franchise record. "It cost us the game. That's horrible."

Boston (37-20) got one last chance, but Al Horford missed a fadeaway jumper as time expired.

It was the second straight win for the Bulls (28-29), who defeated the Toronto Raptors on Tuesday. It was the end of a four-game winning streak for the Celtics.

"Two great ones in a row for us," Chicago coach Fred Hoiberg said. "The Toronto win was key, coming back after finishing the road trip in a tough way, and then bouncing back tonight."

The Bulls hit all 22 of their free throws, including 9 for 9 from Butler, who led six Bulls in double figures with 29 points and seven assists.

Bobby Portis had 19 points off the bench, coming one point short of tying his career high, while Taj Gibson (12 points and nine rebounds) and Robin Lopez (15 points and eight rebounds) also had big games.

Jerian Grant had 10 points and Doug McDermott finished with 11 for Chicago.

Kelly Olynyk had 17 points and Terry Rozier had 11 points off the bench for the Celtics, who got 10 points from Amir Johnson.

Thomas, who scored Boston's final 11 points, missed a jumper with 8.4 seconds left to play. Rather than increasing the Celtics' lead, it gave the ball back to the Bulls for Butler's heroics.

The controversial foul wasn't the only drama between Butler and Smart in the final minute as Smart also stole the ball from Butler with 30.9 seconds left. Smart appeared to have bested Butler again when time ran out, but Butler got the final say.

"It's hard to see from where I was," Hoiberg said. "But it was Jimmy stepping up and making two big ones for us."

Thomas and the Celtics saw it quite differently.

"I might've been the first one to run on the court, and you see him raise his hand up like it was a foul," Thomas said. "The Bulls were even shocked. That's horrible when it costs you a game that you should've won. That's a bad call. We had it won. Great defensive stop by Marcus Smart and the referee called a horrible call. That was bad."

Chicago led 81-78 starting the fourth, but couldn't hold the lead. The Celtics tied it at 92 on a 3-pointer by Rozier with 6:15 left and took a 94-92 lead on a layup by Thomas the next trip down the floor. Thomas scored Boston's next nine points, but the Bulls refused to let a third-quarter comeback go to waste.

After trailing the entire first half, Chicago came out hot in the third and took its first lead with a 12-5 run in the first 3:53 of the frame. Butler's 3-pointer put them up 64-63 with 8:07 left in the quarter to cap the run, and Grant did the same after Boston re-took the lead on its next possession.

Grant's second 3-pointer of the third put the Bulls back up 67-65, and they stayed in front the remainder of the quarter.

NOTES: The Bulls played without starting G Dwyane Wade (right wrist, flu) and rookie F Paul Zipser (left ankle). Zipser missed his fourth game. Wade, who was a part-time participant in practice Wednesday, missed his third game. Wade woke up feeling ill Thursday and didn't attend Chicago's morning shoot-around or the game against the Celtics. ... Bulls F Nikola Mirotic was available off the bench after missing two games with back spasms. ... G Avery Bradley (sore right Achilles tendon) and F Jaylen Brown (right hip strain) didn't play for Boston. Brown missed his third straight game and Bradley missed his 16th. The Celtics hope Bradley can return to the lineup soon after the All-Star break.