Deng scored 25 points and the Bulls played aggressively from the start in their third straight victory, 96-83 on Thursday night.
"We try to keep the tempo up," Deng said. "What we did was great in the second half and we knew they were going to try to jump on us early and we did a good job."
The Bulls led 47-39 at halftime and the Celtics scored the first basket of the second half, a layup by Ray Allen. But Chicago held off several Boston spurts in the third quarter and took a 70-63 lead into the fourth. The lead never dipped below four points after that as the Celtics played without their two best big men, Kevin Garnett and Rasheed Wallace.
That was particularly costly against the second-best rebounding team in the league. The Bulls held a 50-39 advantage on the boards.
"The warning sign for me came in the third quarter," Boston coach Doc Rivers said. "I thought we tried to make a push right out of the box and within two, three minutes, we couldn't sustain. ... I didn't know if we'd win or lose but I knew it would be a tough night."
The Celtics, whose only lead was 2-0, trailed 86-80 after Paul Pierce hit a 3-pointer with 3:50 left. But the Bulls scored eight of the next nine points, six by Joakim Noah, to build the lead to 94-81.
Pierce scored 20 points and Rajon Rondo added 15 for the Celtics. The loss dropped them to 11-6 at home after they went 35-6 there in each of the past two seasons.
"We play three or four games in a row and we come home, we need to make this building a place for teams to feel like they can't win," Pierce said. "We haven't been doing that."
The Bulls won for only the second time in their last 12 road contests as they began a stretch of 10 of 12 games away from home.
Derrick Rose scored 17 points for the Bulls, while Noah had his 19th double-double of the season with 15 points and 11 rebounds.
"It's probably the most complete game we've played all year," Rose said.
The Celtics seemed sluggish and lacked their full complement of players. Garnett missed his eighth game with a hyper-extended right knee and Wallace sat out his third straight with a sore left foot. Rivers said Wallace may return for Boston's next game Monday at home against Dallas, while there's an "outside chance" Garnett could play next Friday at home against Portland.
"Obviously we miss Rasheed. Obviously we miss KG," center Kendrick Perkins said. "But when we come together, it's going to be night and day."
The Celtics were coming off a 111-87 win Wednesday night over New Jersey in which none of their starters played more than 30 minutes. But they got off to a slow start Thursday. They did threaten several times in the second half, coming as close as 75-71 with 8:06 left in the game on a layup by Perkins.
Then the Bulls regained the momentum on consecutive baskets by Deng, Rose and Noah that gave them a 10-point lead.
"We came out with good energy early and we just kept attacking," Chicago coach Vinny Del Negro said.
Chicago's last three victories have all been by double figures, but Thursday's was the first against a good team. The Bulls beat Minnesota 110-96 on Saturday and Detroit 120-87 on Monday, both in Chicago.
"On the road, we've been in some games in the fourth quarter and haven't been able to finish some of them off," Del Negro said. "I was pleased with the way we were able to continually attack in the fourth quarter."
Deng scored 16 points in the first half to help the Bulls to a 47-39 lead at the break. Chicago's biggest lead of the game, 33-20, came on a 3-pointer by John Salmons early in the second quarter.
The Celtics scored the next nine points, cutting the lead to 33-29 midway through the period, but the Bulls regained control by scoring the next six.
"We knew they played four games in five nights and it was important for us to keep the energy going and play a high-paced game," Noah said. "I think when Lu plays the way he did tonight, and Rose played tonight, it was just a team effort."
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