"I thought our guys were pretty locked in today," Celtics coach Brad Stevens said. "We talked about playing with force all day, and I thought we did a pretty good job of that."
Robert Covington scored 25 points to lead Philadelphia.
"That was a bad NBA game tonight from our standpoint," 76ers coach Brett Brown said. "I don't even know what team I coached tonight."
The game originally was scheduled for Saturday but was postponed due to Winter Storm Jonas. With Philadelphia's airport closed on Saturday, the Celtics instead practiced in Boston and arrived in Philadelphia on Sunday morning.
The struggling 76ers have been playing better of late, having won five of 13 coming in, but they looked very much like the team that tied the NBA's worst start at 0-18 this season.
"We didn't want to make the mistake a lot of teams make by looking at their record," Smart said. "We've played them so many times. We know what to do and we kind of relax and they come out real aggressive on us and surprise us. We wanted to come out and make sure we punch them in the mouth first."
Philadelphia has lost 11 games by 20 or more points.
Arriving on the day of the game didn't seem to bother the Celtics at all. Boston cruised to an 18-point halftime lead and then blew the game open in the third quarter when they led by 29 points while outscoring Philadelphia by 10 points to take a 94-69 lead into the fourth.
The Celtics shot 64 percent from the field in the third period. Like the previous two quarters, Boston's players seemingly got wide-open shot after wide-open shot from everywhere on the court.
Philadelphia simply couldn't keep pace.
"We were poor," Brown said. "I don't know why. Maybe it had something to do with the snowstorm. I doubt it. We just didn't come with the energy, for whatever reason."
The Celtics led by as many as 18 points while coasting to a 58-43 halftime lead. Crowder and Smart led Boston with 14 points apiece. The Celtics shot 43 percent from the field, including 62 percent from 3-point range, in the opening 24 minutes.
Covington had 17 points, shooting 5 for 6 on 3-pointers, in the opening half for Philadelphia.
Smart made 6 of 11 shots, including 3 of 6 on 3-pointers. He's been in a season-long slump from the arc, entering at 19.5 percent, and had missed his last seven attempts from long range.
"It felt good," Smart said. "I've been trying to find my rhythm and finally got a few to go down."
Smart likened the game to his AAU days when he'd arrive at the site on the day of the game.
"It was very unorthodox for us," he said.
Stevens credited his players for handling the circumstances well.
"Obviously, that wasn't ideal but I thought our guys were businesslike in our approach," he said.
Celtics: Assistant coach Jerome Allen returned to Philadelphia, where he coached Penn for six seasons before resigning at the end of last season. Allen also starred at the Ivy League school in the early '90's. ... Boston has won all three meetings with Philadelphia this season. ... Former 76ers first-round pick Evan Turner bore the brunt of hecklers throughout the game.
76ers: Due to the weather, the 76ers offered two free tickets to a future home game this season to every fan in attendance among the announced crowd of 9,322, and allowed those with upper-deck tickets to relocate to the lower level. ... Nik Stauskas (left shoulder contusion) returned to the lineup after missing the last three games. Stauskas finished with two points on 1-of-6 shooting. ... T.J. McConnell went to the locker room late in the first quarter after suffering a cut on his right shin when he slipped on a beverage while chasing a loose ball and crashed into a chair in the front row. McConnell returned later in the half. Brown said McConnell was the lone 76er who played well. He had eight points.
Celtics: At Washington on Monday.
76ers: Host Phoenix on Tuesday.