DALLAS -- For those who believe Russell Westbrook is a one-man team, Monday night did little to change their minds.

Westbrook singlehandedly spearheaded a 14-0 game-ending run, capped by his 18-foot jumper in the closing seconds, to lift the Oklahoma City Thunder to a 92-91 win over the Dallas Mavericks at American Airlines Center.

Westbrook scored 12 of the final 14 points.

"I guess I just come out and compete every night," he said. "I just try to find ways to help my team win and always keep a 'never quit' mentality and always keep it going."

The Thunder (42-31) were in trouble for much of the game, and they trailed by as many as 14 in the fourth quarter. However, after the Mavericks went up 91-78, Dallas didn't score again.

Westbrook's final shot from just inside the top of the key connected with 7.2 seconds left. Harrison Barnes missed a long 3-pointer at the buzzer for Dallas.

Westbrook racked up his 37th triple-double with 37 points, 13 rebounds and 10 assists. He needs four more triple-doubles in the final nine games to tie Oscar Robertson's single-season record of 41 set in 1961-62.

Oklahoma City improved to 30-7 this season when Westbrook notches a triple-double. The Thunder had won 11 in a row in such games before a 137-125 loss at the Rockets on Sunday.

"It's very important, especially after how we lost yesterday," Westbrook said. "I wasn't completely happy with how we played, but I thought we came out and competed at a high level for 48 minutes."

Victor Oladipo had 15 points and nine rebounds for the Thunder, and Taj Gibson had 13 points and six boards.

Dallas reserves Devin Harris, J.J. Barea and Salah Mejri led the way for the home team, combining for 30 points, 12 rebounds and 10 assists. That trio also had the team's three highest point differentials, each at least a plus-8. All five starters were in negative figures.

"All of our bench guys were a plus," Dallas coach Rick Carlisle said. "Some nights the bench plays well and the starters struggle, and vice versa. Tonight was a night when we needed everybody to play an even, consistent, hard-playing game."

Westbrook missed a potential go-ahead shot with about 20 seconds left. The Mavs (31-42) rebounded the miss and called timeout. Dallas lost the ball on the inbounds pass, as Westbrook pressured Barea on the sideline.

With the ball in his hands, Westbrook gave Oklahoma City its first lead of the second half when it mattered most.

"When the ball was being taken out of bounds, it gave him a head of steam," Thunder coach Billy Donovan said. "He can get a full run and you're kind of backing up because at that point you're worried about him getting to the rim. But then he obviously creates that space with his speed, and then he can stop when he gets to 15 feet -- that's about as good a shot as you're going to get."

The Thunder's game-ending run left the Mavs stunned.

"It just happened so fast," Nerlens Noel said.

Noel had 15 points and eight boards for Dallas, with Wesley Matthews also scoring 15.

Oklahoma City came out firing in the third quarter, cutting 14 points off a 15-point deficit to get within 56-55. The Mavs would respond with a 10-0 spurt and were back up 69-57 going into the fourth.

The Mavericks took a 26-25 lead with a 12-4 run to end the first quarter and took control by dominating the second. Dallas scored the first 10 points of second period on its way to a 45-30 advantage.

That 15-point lead remained intact going into halftime at 50-35. Noel had 10 points and six boards at the break, with Matthews scoring nine.

Westbrook was a one-man show with 17 points, eight rebounds and five assists in the first half, but received little help. His teammates combined to shoot 28 percent (7 of 25) in the first half.

After a 1-3 homestand, the Mavs open a five-game road trip Wednesday at New Orleans.

Oklahoma City looks to finish off a 2-1 road trip Wednesday at Orlando.

NOTES: Dallas coach Rick Carlisle isn't betting against Thunder PG Russell Westbrook finishing the season averaging a triple-double. "If he puts his mind to it, he can pretty much do anything on the basketball court," Carlisle said. ... Dallas clinched its first losing season since 1999-2000. ... Oklahoma City improved to 1-6 on the second night of a back-to-back after losing the first game. ... Mavericks PG Seth Curry (shoulder) was out and PG Yogi Ferrell (13 points) started in his place. ... The Thunder improved to 7-6 in March. ... The Thunder won the season series 2-1. ... The Mavs recalled G Manny Harris and F Jarrod Uthoff from the Texas Legends of the NBA Development League. Neither played Monday night.