And ran up some impressive numbers.
"The offense has gotten better over the last couple of weeks," Stevens said. "We just have to keep building on it."
Jayson Tatum had 18 points and Terry Rozier added 15 as the Celtics used a 17-0 start and a balanced attack to roll their second straight lopsided win after beating New York 128-100 on Thursday. The Celtics have outscored opponents an average of 126.2 to 97.6 during their five-game run.
"I think since the last five games, we've been moving the ball very well, probably average 30 assists in every game we won," Theis said. "That's the way we should play — just fast."
The 56-point loss was the worst in Bulls' history, eclipsing a 53-point (127-74) defeat at Minnesota on Nov. 8, 2001.
"Disappointing effort, disappointing outcome after what I thought was a really hard-fought two games and at home last night," coach Jim Boylen said. "Got to give Boston credit, I thought they made the shots.
"They kind of punched us and we didn't respond."
Shaquille Harrison came off the bench to score a career-high 20 points for the Chicago, which has lost eight of nine. Zach LaVine had 11 for the Bulls (6-21), whose previous worst loss this season was by 39 points (122-83) to Toronto on Nov. 17.
"We all should be (embarrassed)," LaVine said.
The Bulls fell flat after beating Oklahoma City 114-112 on Friday night on Lauri Markkanen's layup in the closing seconds, giving Boylen his first win as an NBA head coach.
A longtime NBA assistant, Boylen took over Monday when Fred Hoiberg was fired following a 5-19 start. The Bulls lost at Indiana the following night in Boylen's debut.
The Celtics took charge early in this one, racing ahead 17-0 as they shot 8 for 11 from the floor at the start. Boston led 35-17 after one quarter as it shot 60.9 percent, and led 64-43 at the half thanks to 52.4-percent shooting.
For the game, the Celtics outshot Chicago 53.8 percent to 38.3 percent.
The scoring in Boston' first-half outburst was evenly distributed. Marcus Morris led with 12 points, while Tatum, Theis and Rozier each had 10.
The Celtics' biggest lead in the first half was 22 points and Chicago never got closer than 13.
Chicago missed its first 12 field goal attempts, prompting Boylen to pull all five starters 4:45 in. The Bulls didn't score until Jabari Parker hit a pair of free throws 6:18 in — raising a derisive cheer from the United Center crowd. Chicago didn't get its first basket until Robin Lopez sank a turnaround hook 36 seconds later.
The Celtics kept the pressure on, outscoring Chicago 69-34 in the second half.
TIP-INS
Celtics: Forward/center Al Horford missed the game with a sore left knee after recording 19 points and 12 rebounds against New York on Thursday. ... Forward/center Aron Baynes (sprained left ankle) also sat out. He limped off the court late in the last two minutes of the first quarter on Thursday versus the Knicks. ... Forward Guerschon Yabusele had to be helped off the court midway through the fourth quarter after landing awkwardly. Stevens said Yabusele suffered a "bad sprain."
Bulls: Boylen still isn't sure when guard Kris Dunn (sprained left MCL) and forward Bobby Portis (sprained right MCL) will return. "Long-term health is what we're about," Boylen said. "We expect them back soon, any day, but not today. We'll re-evaluate tomorrow." . A longtime NBA assistant, Boylen said he's very close to Hoiberg and said feelings are still "really raw" following the firing of his former boss. Boylen shook off questions about whether Hoiberg "lost the locker room." ''I approach the locker room different than Fred," Boylen said. "It doesn't mean better, worse or whatever. We're different people."
BY THE NUMBERS
The Celtics have scored at least 115 points in five straight games in their winning streak, their longest such run since doing it six consecutive times in March 1988.
GOT MILK?
Boylen said he celebrated his first victory as an NBA head coach on Friday night at home with his family. "We had a bowl of cereal with my kids and watched the 'Family Feud,'" he said.
UP NEXT
Celtics: Host New Orleans on Monday.
Bulls: Host Sacramento on Monday.
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