Five Boston Celtics players ended with double figures in points as the champions overcame a resilient Cleveland Cavaliers side led by Donovan Mitchell with solid support from Darius Garland.
Jayson Tatum led Celtics scoring with 22 points in Ohio, while Derrick White scored 14 of his 20 points in the fourth quarter to help the visitors to a 112-105 win – their fourth successive victory in the NBA.
Spida finished with 31 points and 10 rebounds as he led the Cavs with a double-double, while Galand added 25 points and Jarrett Allen posted 17 points and 18 rebounds in a futile effort for the Eastern Conference leaders.
Elsewhere in the NBA on Tuesday night, Lakers thrashed city rivals, Clippers, but 25 points, 76ers edged the Mavericks by two points, same as Brooklyn Nets did against the Houston Rockets, while Miami Heat fell by nine points in Chicago.
The New York Knicks got the better of the Toronto Raptors while Portland Trail Blazers have now won nine of their last 10 after easing past Indiana Pacers.