Brown hit a crucial three-pointer in the closing minutes as Boston held on in a thrilling game in which the lead changed 19 times.
Pascal Siakam led the way for the Raptors with 33 points, while Kyle Lowry scored 29.
LeBron James had 32 points, 10 assists and seven rebounds to lift the Los Angeles Lakers to a 95-86 victory over the visiting Utah Jazz.
The Chicago Bulls overcame a nine-point half-time deficit to score a 110-102 victory at the Memphis Grizzlies, with Zach LaVine reaping 37 points.
Coby White chimed in with 25 points, 21 of them in the second half as the Bulls fought back.
And the New York derby ended with the Brooklyn Nets beating the Knicks 113-109, with Kyrie Irving scoring 26 points, including a three-pointer to take the lead with 22 seconds left.
Elsewhere, the Minnesota Timberwolves thrashed the Charlotte Hornets 121-99 and the Dallas Mavericks won 123-116 at the New Orleans Pelicans.
The Washington Wizards were 97-85 winners at the Oklahoma City Thunder, the Denver Nuggets beat the visiting Phoenix Suns 108-107 in overtime and the Portland Trail Blazers won 122-112 at the Sacramento Kings.