Isaiah Thomas had 23 points and 10 assists, and the Boston Celtics handed the Chicago Bulls their first loss of the season, 107-100 on Wednesday night.

 

Amir Johnson also finished 23 points, including four 3-pointers, to help the Celtics avenge their lone loss of the season.

 

Boston played without center Al Horford, who was placed in the concussion protocol Tuesday after exhibiting concussive symptoms during practice.

 

Johnson helped pick up the slack without him, scoring 16 points in the third quarter. The Bulls managed just 18 points in the period, their lowest scoring quarter of the season.

 

The Bulls cut into what had been a 16-point Boston lead in the fourth quarter and tied it at 100 on two free throws by Nikola Mirotic. But Boston regained the lead 101-100, then went up five on a driving layup by Thomas and basket by Marcus Smart.

 

Jimmy Butler led Chicago with 23 points and nine rebounds.