Nowitzki scored 11 of his season-high 41 points in overtime and the Mavericks held on to beat the injury-depleted San Antonio Spurs 99-94 on Wednesday night.
Drew Gooden added 17 points and 11 rebounds before fouling out late in the fourth quarter, and Dallas extended its winning streak to four games.
Gooden, who finished last season with the Spurs before signing with the Mavericks on July 20, started at center with Erick Dampier out because of an unknown illness. Dallas was also without starters Josh Howard and Shawn Marion because of left ankle injuries.
"With Josh out and Marion out, I've just got to keep going offensively and make things happen," Nowitzki said after his 14th career game of 40 or more points.
Nowitzki's three-point play with 2:28 left in overtime put Dallas in front for good, 92-91. After Jason Terry hit a 15-footer, Nowitzki made a 3-pointer on Dallas' next possession to stretch the lead to 97-91, closing out the Spurs.
"He's playing great basketball and (I) think he's one of the top guys right now in the league," Gooden said. "He's really playing at a high level. We need that because of all the injuries we have right now and he's doing everything he can to carry this team."
Nowitzki went 15 for 29 from the field, converted 10 of 12 free throws and pulled down 12 rebounds to continue a big week for the German superstar.
Nowitzki's buzzer-beating overtime jumper gave Dallas a 115-113 victory at Milwaukee on Monday night after he scored 25 in a 95-90 road win over Detroit on Sunday.
"I hoped he was having an off night," said Matt Bonner, one of several Spurs who tried to guard Nowitzki. "I can play perfect defense and jump as high as I can and he can still score."
Tim Duncan had 22 points and 14 rebounds for the Spurs, winless in four road games this season.
Duncan missed all three shots and went scoreless in overtime, and afterward he blamed himself for the loss.
"I know I played badly in the overtime," Duncan said. "The OT wasn't good for us and Dirk really took over and won it for his team."
The Spurs were without starting guard Tony Parker, who aggravated his sprained left ankle in Saturday night's loss to Oklahoma City. San Antonio also lost guard Manu Ginobili in the first quarter due to a strained left groin.
"We definitely needed this win because they were without Ginobili and without Parker," Nowitzki said.
The Spurs certainly missed two of their stars, but the Mavericks were equally short-handed.
"With Tony out and then how Manu went out, it hurt not having them in there," Duncan said. "But I thought we did a good job keeping it together."
With the game tied at 80, Gooden was credited with a basket on a goaltending call against Antonio McDyess with 1:58 left in regulation to put Dallas ahead.
Duncan drove to the basket on the next possession and Gooden picked up his sixth foul. Duncan knocked down both free throws to knot the score at 82 with 31 seconds remaining.
Nowitzki's tip-in 17 seconds later gave Dallas an 84-82 lead, but Duncan's jump-hook with 2.3 seconds remaining drew San Antonio even.
The Mavs had a shot to win in regulation, but Duncan blocked Terry's 19-footer at the buzzer.
NOTES: Ginobili started and scored two points in eight minutes of the first quarter, then went to the locker room before the start of the second quarter and was done for the night. Coach Gregg Popovich said Ginobili would sit out Thursday night's home game against Utah. ... Marion was hurt in a game at Milwaukee on Monday night. ... Howard missed his eighth game as he recovers from offseason surgery. ... Dampier has been undergoing tests to determine the nature of the illness, and results won't be known until next week. ...Thomas made his debut for Dallas after sitting out the first 11 games while he completed his recovery from offseason surgery on his right knee. Thomas, who finished with two points in 14 minutes, was signed as a free agent on July 28.