The Celtics held double-digits leads at the end of every quarter and were hardly tested. The Rockets, who beat New Jersey on Saturday, appeared worn down from the start.
"They were much more assertive, aggressive on the boards, on every loose ball, they were just playing harder than we were tonight," Houston coach Jeff Van Gundy said.
LaFrentz, averaging just 9.2 points per game, connected on four 3-pointers in the opening 9:16 that helped Boston open a 24-12 lead. He hit three 3-pointers in the final 3:35 of the second quarter that gave the Celtics a 55-44 lead at the half.
LaFrentz finally missed his first 3-point attempt 5:30 into the third quarter.
The Rockets closed it 57-49 on McGrady's basket early in the third quarter and stayed within 13 points until the Celtics broke it open with a 18-7 run to close the quarter. Boston led 84-63 after three.
"LaFrentz got off to such a great start because of our mistakes," McGrady said.
The only suspense the rest of the game was whether LaFrentz would establish a career-high, which he had a chance for with 3:29 to play. He missed a free throw that would have completed a three-point play. LaFrentz came out with 2:31 remaining.
Boston's bench, led by Davis, was cheering for LaFrentz to get his career high.
"No, I had no idea," LaFrentz said with a smile when asked if he knew he was close.
LaFrentz scored 32 points with Denver on April 18, 2001.
LaFrentz fell one short of the NBA record for 3-pointers in a half, held by five players. McGrady was the last, doing it on Jan. 26, 2004. ... Van Gundy talked about how slow his team was before the game. He was proved correct, especially in the game's opening minutes. ... Pierce closed the second quarter with an off-balance runner at the buzzer.