Nowitzki scored 30 points, 19 in the final quarter, and Josh Howard matched a career high with 30 points as the Mavericks bounced back from consecutive defeats, rallying from a 10-point halftime deficit to beat the Boston Celtics 106-101 on Friday night.
Howard kept the Mavericks close with 16 first-half points, and Nowitzki carried his team down the stretch, hitting all five field-goal attempts and all nine free throws in the fourth quarter.
"He's our leader and we follow him," Howard said of Nowitzki. "Leaders do what it takes to get us a win and he did that."
Nowitzki, Dallas' top scorer and rebounder, had only four first-half points and missed five of six from the field.
But Nowitzki finished strong, going 8-for-12 from the floor and pulling down nine rebounds in the second half to lift the Mavericks to 17-1 when he scores 30 or more.
"It was a weird game for me," Nowitzki said. "I had a tough time getting going. I've had some trouble sleeping the past couple nights. I think I was sleepwalking a little bit. ... It wasn't a great effort but it's good to get the win."
The Mavericks had a club-record streak of 23 straight wins at home snapped with Wednesday night's 129-127 double-overtime loss to the Phoenix Suns. Dallas had won a team-record 17 in a row before a loss to the Golden State Warriors on Monday night.
Dallas' two-game losing streak was its longest since opening the season at 0-4.
Paul Pierce scored 29 points, Gerald Green had a career-high 25, and Al Jefferson finished with 20 points and 10 rebounds to pace the Celtics, who had won six of their previous nine.
"At his point, we have nothing to lose," Pierce said. "We're out of the playoff race and we're just playing for pride."
Dallas led 100-97 when Nowitzki passed to Jerry Stackhouse for a dunk with 1:16 left.
After Pierce hit two free throws, Nowitzki converted twice from the free-throw line with 47 seconds left for a 102-99 lead.
Nowitzki clinched the victory when he made a 13-foot fadeaway over Jefferson for a 104-99 lead with 4.8 seconds remaining.
"Dirk was a little flat in the first half," said Dallas' Jason Terry, who had 16 points. "But he said he'd be there when we needed him and he came through in the fourth quarter with the game on the line."
With the score tied at 85, Stackhouse had a 3-point play with 5:46 left to give the Mavericks the lead for good. Dallas improved its home record to 31-4.
"It was a great effort," Celtics coach Doc Rivers said. "That's as close to the playoffs as we're going to get. We had a couple of possessions our young guys need to learn from. We took some quick shots and they (the Mavericks) hit some big shots."
Terry and Howard combined for Dallas' first 18 points of the third quarter. Then Nowitzki scored the final eight to reduce Boston's lead to 70-69 entering the fourth quarter.
Pierce got off to a fast start, hitting seven of his first eight field-goal attempts and scoring 17 of Boston's first 21 points. But Pierce picked up two early fouls and played only seven minutes of the first quarter.
Rivers feared that Pierce would pick up a third foul so Rivers kept his top scorer on the bench until there were five minutes left in the half.
Even with Pierce sitting for much of the first half, the Celtics converted 15 of their first 24 shots from the floor and grabbed a 54-44 halftime lead behind Pierce's 19 points.
"Our energy level wasn't what it needed to be in the first half," Terry said. "We were coming off a tough, emotional loss that was draining. So it was good to see us respond to adversity and pick it up in the second half."
Dallas was without two of its top defenders: guard Greg Buckner (sprained left knee) and swingman Devean George (sprained right knee). Coach Avery Johnson said Buckner is out indefinitely after injuring the knee in the fourth quarter against Phoenix.
Howard also had 30 points against Denver earlier this season. ...The Celtics connected on their first four 3-pointers, three by Pierce, and shot 58 percent from the field (19-for-33). Boston was 6-for-8 from 3-point range in the first half. ... Dallas has won the past six meetings with Boston and 12 of the past 13.