There's a big difference between a team closing in on a No. 1 seed and another just hoping to remain in contention for a playoff spot.
Marbury felt he had to do it alone for the injury-depleted New York Knicks. Nowitzki had help, though he didn't need much.
"In the fourth, I wanted to go into attack mode and make stuff happen," Nowitzki said.
Nowitzki scored 17 of his 30 points in the fourth quarter, including nine straight in the final 1:56, and the Mavericks beat New York 105-103 Friday night for their franchise-record 61st victory.
Marbury had a season-high 43 points, but his undoing at the end kept the Knicks from forcing overtime. After twice putting the Knicks ahead in the closing stretch, his bad pass with 21 seconds left was stolen by Jason Terry. Marbury's final shot was blocked to end the game.
"It's a learning experience when we got that turnover. They were trying to double and get the ball out of my hands," Marbury said of his attempted pass to Renaldo Balkman. "But he got caught up and couldn't get there. He's a rookie."
A three-point play by Marbury put the Knicks up 101-100 with 1:18 left. Nowitzki then made two free throws, but Marbury answered with another basket.
"This is the best basketball I've ever seen him play in this league. Mentally, physically, he's been a rock," Knicks coach Isiah Thomas said. "He did everything he could possibly do for us tonight. It's a bitter and tough loss but it's one we have to learn from."
Dallas went ahead for good after Nowitzki gave the ball up with a pass to a wide-open Jerry Stackhouse. After Stackhouse missed the 3-pointer, Nowitzki grabbed the rebound and made both free throws after being fouled.
Terry hit the second free throw after the steal and a foul with 17 seconds left. Marbury couldn't make up for his mistake, his last shot blocked by Josh Howard.
"We hate the thought of losing. When it's a tight game we're going to do the necessary things to win," Terry said. "But it's not about winning streaks or wins in the regular season. It's about momentum. So when we get to the playoffs we'll be hitting on all cylinders."
The Mavericks, who have won nine straight games, next play Sunday at Phoenix with a chance to move closer to clinching the No. 1 seed in the Western Conference for the playoffs. They can also become the first NBA team ever to have four winning streaks of at least 10 games in the same season.
And they still could join the 1995-96 Chicago Bulls (72-10) as the only teams to reach the 70-win plateau. They would have to win nine of the last 10 games.
The Knicks are two games behind New Jersey for the No. 8 spot in the Eastern Conference, even though they scored more than 100 points for the first time in 11 games.
"We played with a different mentality tonight. If we play like that the rest of the way, we'll give ourselves a chance to win," Marbury said. "Tonight we played with a lot of intensity. ... We showed we want to make the playoffs."
On his first basket of the game, Nowitzki surpassed 15,000 points. He came out of Wednesday night's game with a sore left ankle, playing only a minute after halftime, stuck at 14,999.
Nowitzki hadn't made a field goal since the 4:46 mark of the second quarter when he made three within two minutes early in the fourth quarter, taking the Mavericks from their first second-half deficit to an 84-81 lead.
Even after their worst shooting quarter of the season, going only 2-of-19 (11 percent) in the third quarter, the Mavs didn't lose their lead, though the Knicks tied it at 76.
Dallas was only 1-of-8 in the third quarter when it extended the lead to 67-57 on two free throws by Devin Harris. The Mavs made 15 of 17 free throws in the quarter, the only thing that kept them from falling behind.
Nate Robinson, who started for injured Steve Francis, had a layup to start the fourth quarter and put the Knicks ahead. Nowitzki followed with his first surge of the fourth quarter, and wasn't finished.
Robinson had 15 points, while Eddy Curry had 17.
Howard added 20 points for the Mavs. Terry had 14, including two tiebreaking 3-pointers in the final quarter.
Marbury scored 23 points in the first half, but Dallas used an 8-2 run over the final 1:40 to lead 57-53. Erick Dampier had consecutive short jumpers before Stackhouse's half-ending alley-oop dunk from Harris.
Nowitzki is the 105th NBA player with 15,000 points. ... The last time New York had scored 100 points was March 3 in a 104-100 overtime victory against Atlanta. ... Knicks forward Quentin Richardson is out for the rest of the season after back surgery Thursday. ... Francis is also expected to miss Saturday's game against New Orleans. New York was also without forward David Lee (leg) and Jamal Crawford (ankle). ... Dallas will sign 44-year-old forward Kevin Willis to a 10-day contract Monday -- if he passes a physical. The 7-foot Willis is a veteran of 20 seasons who last played 29 games for Atlanta in 2004-05.