Jayson Tatum led six Celtics in double-figures with 19 points in a 118-110 win over the Detroit Pistons at TD Garden in Boston.
Al Horford had 17 points, 14 rebounds and eight assists for Boston, which has won seven of its last nine games.
Kyrie Irving sat out for the second straight game with a knee strain.
The Celtics enter the All-Star break at 37-and-21.
Blake Griffin led Detroit with 32 points. Andre Drummond contributed 21 points and 17 boards for the Pistons, who had their four-game winning streak snapped to fall to 26-and-30.
The Pistons are off for the All-Star break and will return to action next Friday when they visit the Hawks in Atlanta.
Griffin is the lone representative for Detroit in the NBA All-Star Game, which will be played Sunday in Charlotte, North Carolina.