DEnnis Schroder had 38 points, a season-high eight in overtime, and the Boston Celtics outscored the Milwaukee Bucks 122-113.
The Celtics took advantage of Giannis Antetokounmpo’s absence to beat the Bucks.
Boston has won four of five since opening the season at 2-5.
Jayson Tatum had a double-double of 27 points and 11 rebounds and Marcus Samart had 19 points.
Dominican Al Horford had nine points in 30 minutes of play.
Horford made 3 of 10 shots from the field, including 1 of 6 triples, and 2 of 2 from the personnel line, had seven rebounds and gave five passes for scoring for the Celtics (6-6).
For the Bucks (6-7), defending NBA champions, the leading scorer was Bobby Portis with 22 points.
Grayson Allen scored 21 and Jrue Holiday had a double-double of 17 points and 13 assists.
Allen hit a pair of 3s in the final 73 seconds of regulation time to send the game into overtime.
Antetokounmpo, the current Most Valuable Player (MVP) of the NBA Finals, was ruled out 90 minutes before the game due to a sprained right ankle.
Pat Connaughton started in his place and scored 15 points when the Bucks lost for the sixth time in their last nine games.