1 of 5
Tim Sharp, Associated Press
Oklahoma City Thunder guard James Harden (13) drives in front of Dallas Mavericks forward Dirk Nowitzki (41), of Germany, and guard Jason Terry (31) during the first half of an NBA basketball game Monday, Jan. 2, 2012, in Dallas.

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 came in 5-0, the last unbeaten team in the NBA. One of their wins was a buzzer-beater over the Mavs in Oklahoma City.

Despite playing for the fourth time in five days, Dallas finally looked like the reigning champions, especially in the middle two quarters. The Mavericks outscored the Thunder by 13 in that span and played stellar defense, especially while giving up only 18 points in the third quarter.

Kevin Durant led Oklahoma City with 27 points. Russell Westbrook scored 18 and James Harden had 16.

Shawn Marion scored 17 points for Dallas, and Jason Terry added 15.