MAVERICKS 103, THUNDER 97: James Harden scored 15 of his playoff career-high 29 points in the fourth quarter and visiting Oklahoma City completed a four-game sweep of the defending NBA champions.

Kevin Durant added 24 points and 11 rebounds as the Thunder stormed back from a 13-point deficit in the final 9 1/2 minutes to end Dallas' reign.

Oklahoma City withstood a sub-par performance from All-Star point guard Russell Westbrook (12 points) and a first-quarter injury to starting center Kendrick Perkins to avenge last season's five-game playoff series loss to the Mavericks.

Dirk Nowitzki had 34 points to pace Dallas, which became the first defending champion to be swept in the first round since Miami in 2007.

The Mavericks appeared to be in control when Jason Terry nailed a 3-pointer for an 86-73 lead, but Harden scored nine points in a 12-0 spurt before Durant buried a 3-pointer to tie it at 88 with 6:05 left.

Nowitzki put the Mavericks back ahead with a three-point play, but the Thunder answered with eight straight points to cap a 23-5 run for a 96-91 lead with exactly 3:00 to play.

The 2011 NBA Finals MVP hit a pair of free throws to cut the deficit to 100-97 with 33 seconds left. Harden responded by driving the lane for a finger roll with 10.2 seconds left to seal it.

Nowitzki hit his first four shots of the third quarter to help Dallas break away from a 47-47 halftime tie and build the double-digit lead. Jason Kidd buried three 3-pointers to extend the margin to 81-68 entering the fourth.

GAME NOTEBOOK: Perkins suffered a right hip strain with about four minutes remaining in the first quarter and did not return. His status for the remainder of the postseason is unclear. Perkins averaged 5.1 points and 6.6 rebounds and missed only one game during the regular season. ... Dallas scored 34 points in the third quarter, the most by either team in any quarter in the series until the Thunder scored 35 in the fourth quarter. ... The Mavericks made a change to their lineup, giving sixth man Jason Terry only his second start of the season in place of Delonte West. ... Mavericks owner Mark Cuban said he will not address the status of coach Rick Carlisle until after the season. Carlisle's contract expires July 1.