The National Basketball Association champions Dallas Mavericks were swept out of the first round of the playoffs on Saturday as the Oklahoma City Thunder wrapped up their Western Conference series with a 103-97 victory.

James Harden scored 15 of his 29 points in the fourth quarter as the Thunder won their fourth straight in the best-of-seven series to make the Mavericks the first defending champions to be swept in the first round since the Miami Heat in 2007.

Kevin Durant added 24 points and 11 rebounds and Russell Westbrook finished with 12 points, six assists and five rebounds for the second-seeded Thunder. They became the first team to reach the second round, where they will face either the Los Angeles Lakers or the Denver Nuggets.

Dirk Nowitzki, the Most Valuable Player of last season's NBA finals triumph over Miami, led the Mavericks with 34 points and Jason Kidd added 16 with eight assists and seven rebounds.

Elsewhere in the West, the Los Angeles Clippers rallied for a dramatic 87-86 victory over the Memphis Grizzlies for a 2-1 lead while in Salt Lake City, Tony Parker scored 27 points to lead the San Antonio Spurs over the Utah Jazz 102-90. The victory put the top-seeded Spurs on the brink of advancing as they took a 3-0 lead in the series. Tim Duncan scored 17 points and Danny Green 14 for the Spurs.

In the East, the Indiana Pacers squandered a 19-point lead against the Orlando Magic but fought back in overtime to register a 101-99 victory and take a 3-1 series lead.

In Dallas, Mavericks coach Rick Carlisle said the Thunder were just too good for the defending champions.

"They're a great young team," Carlisle said of the Thunder. "And the thing that impressed me most about them is that they have a certain look in their eye right now, not just that they belong, but that this could be their time."

Dallas, just the third defending champion to be ousted in the first round, failed to score a field goal in the final 5:47.

Oklahoma City had trailed by 13 at the end of the third but sparked to life by a 12-0 run, they finally took the lead on a slam dunk by Serge Ibaka with five minutes to play.