He scored 28 points despite shooting 9 of 23 and led a late rally for the Mavericks' 106-102 overtime victory over the Memphis Grizzlies on Wednesday night.
Nowitzki made six of his final eight shots.
''He's the type of guy that has so much confidence in his shot,'' Brendan Haywood said. ''His shot is so pure that you know eventually he's going to start making them.''
Jason Terry scored 29 points for the Mavericks, who have now won 50 games in each of the last 10 seasons. Jason Kidd had 12 points, 10 rebounds and seven assists, and Caron Butler had 11 points and a season-high 13 rebounds.
Memphis held a 13-point lead with 4:25 left in regulation before Nowitzki came out of his shooting slump to help the Mavericks pull even.
''They probably relaxed a little bit,'' Haywood said of the Grizzlies' double-digit lead in the fourth. ''It's human nature. They probably thought: 'OK, we've got this one.'
''Next thing you know, a bucket here, a bucket there, a couple of threes, some missed free throws, and we're back in the game.''
The teams were tied at 90 at the end of regulation as Nowitzki scored 10 of the Mavericks' final 11 points in the fourth quarter.
Dallas was able to hang on after building a 5-point lead in overtime. Nowitzki had six points in the final 24 seconds, including all four of his foul shots.
Nowitzki said a 3-pointer he made late in the third sparked his late run.
''As a shooter all you need is to see one go through,'' Nowitzki said. ''Sometimes it might be a free throw. Sometimes it might be a layup that gets you going. I was just happy that one went through.''
Memphis, which had built a double-digit lead at the start of the second half, was still up 84-73 at the midway point of the final period.
But Nowitzki keyed the final charge, erasing the Memphis advantage.
Dallas converted two steals into baskets to start the overtime, and eventually Kidd would connect on a 3-pointer for a 97-92 lead.
Memphis was within 101-100 when Randolph hit a pair of free throws with 13.8 seconds left in overtime. But Nowitzki hit four free throws down the stretch to preserve the victory.
''We can't close out games,'' Randolph said. ''That has been a big problem for us the whole season. We have to learn how to do that.''
Turnovers plagued both teams in the first half, Memphis committing nine, while the Mavericks had 13. The Mavericks had an inbound violation after a Grizzlies' basket and a lane violation at one point. Memphis, meanwhile, not only committed turnovers, but missed dunks and layups.
The teams were tied at 50 at halftime. Conley had 16 points for Memphis, while Randolph scored 13. Terry came off the bench to lead the Mavericks with 15 points in the half.
Memphis opened the second half with a 17-4 run to claim its biggest lead. Nowitzki was struggling from the field, missing 11 of his first 14 shots. The rally helped Memphis hold a 73-67 lead entering the fourth quarter - before Nowitzki and the Mavericks came back.
''This team doesn't have any quit in them,'' said Haywood, who came to Dallas in a deadline deal from the Washington Wizards . ''We're not going give in. As long as we think we have a shot, we're going to continue to fight and play hard.''
NOTES: The Mavericks were 11 of 28 from outside the arc, and have hit at least eight 3-pointers in each of the last six games. ... Including Wednesday's game, eight of Memphis' final nine games are against teams with winning records. ... Since the league went to an 82-game schedule in 1967-68, only two other teams - the Lakers in the 1980's and the San Antonio Spurs - have compiled 10 straight seasons of 50 wins. The Lakers had 12 straight, while the Spurs currently have 10 in a row. ... The Mavericks had lost three straight in Memphis before Wednesday's victory. ... Officials reviewed Butler's 3-pointer at the end of the first quarter before confirming that it occurred before the horn. Butler launched it from more than 30 feet off the right wing, banking in the shot.