DALLAS — Dirk Nowitzki scored 10 of his 26 points during the third quarter, sending the Dallas Mavericks to a 100-87 victory over the Oklahoma City Thunder on Monday night.

The Thunder, who topped Dallas on a buzzer-beater in Oklahoma City on Thursday, came in as one of only two unbeaten teams in the NBA at 5-0. Miami was the other but the Heat lost to Atlanta 100-92 earlier Monday night, also falling to 5-1.

Dallas began pulling away with a 9-2 run at the start of the second quarter, but Oklahoma City kept clawing back to keep things close. Then Nowitzki took over.

He opened the second half with a jumper over Kendrick Perkins that left the big man snarling at his own bench. He made another shot with defender James Harden ducking for cover, then scooped in a layup on a play that began with Delonte West spinning Harden to the floor. The layup put Dallas up by 15 and the game wasn't close again.

The Mavs came in 1-4 with a victory over lowly Toronto. Their best effort probably had been their loss at Oklahoma City. Yet before the game, coach Rick Carlisle said, "I don't think we're as far off as it may appear." Dallas fixed two flaws by scoring 56 points in the paint and keeping the rebounds even at 41.

Nowitzki was 10 of 16, with four of his misses from 3-point range. He had six rebounds, three assists and two steals.

Shawn Marion scored 17 points, Jason Terry 15 and Vince Carter a season-high 14 — eight on free throws — for Dallas. Jason Kidd didn't score but had a season-high nine assists.

Oklahoma City's Kevin Durant scored 27 points, but had only four during the pivotal third quarter. Russell Westbrook added 18 points and eight rebounds, and Harden had 16 points and seven rebounds.

Notes: Nowitzki made a 10-foot, stepback jumper at 7:40 of the second quarter for his 8,000th career basket. He's fourth among active players (behind Kobe Bryant, Kevin Garnett and Tim Duncan) and 31st on the NBA career list. ... Oklahoma City's Daequan Cook (flu) was inactive. Thabo Sefalosha also had a touch of flu, but started. He didn't play the second half because of a sore right foot. ... The Mavericks don't play in Washington, D.C., this season, but they're headed there on Monday for the annual champion's visit to the White House. Team president Terdema Ussery set it up after the club realized the omission on the lockout-condensed schedule. Mavs owner Mark Cuban said "the league office was stupid or dumb or worse" to let that happen.