Kevin Durant finally found his postseason shooting touch to get Oklahoma City off to a quick start, and the Thunder never trailed on the way to a 95-79 victory over the Dallas Mavericks on Thursday night for a commanding 3-0 series lead over the defending NBA champs.
After two close games on their home court, the young Thunder ran away with Game 3.
They will run away with the first-round series with one more win. Game 4 is Saturday in Dallas.
"You have to win four. ... We'll play every game like it's the most important game. We've done that all year and continue to do that," Thunder coach Scott Brooks said. "(The Mavericks) have pride, they're not going to give you anything. They're going to make you earn it. We earned it."
Even though Durant missed the first shot of the game, Serge Ibaka turned that into a putback basket. Durant then scored nine points in an early 3-minute span, including two 3-pointers and a 17-foot fadeaway, as Oklahoma City took a 14-7 lead.
Durant finished with 31 points on 11-of-15 shooting. The three-time NBA scoring champion was a combined 15 of 44 in the first two games of the series, though he had a game-winning jumper with 1.5 seconds in the opener.
"He was jumping over us and making shots," Dallas coach Rick Carlisle said.
Russell Westbrook added 20 points for the Thunder, while Ibaka had 10 points and 11 rebounds and James Harden and Derek Fisher both had 10 points.
Dirk Nowitzki had 17 points to lead Dallas, and Jason Kidd had 12.
The Mavericks have a nearly impossible climb to avoid being the first defending champion knocked out in the first round of the playoffs since Miami five years ago. After beating Dallas in the 2006 NBA finals, the Heat were swept in four games by Chicago in the opening round of the Eastern Conference playoffs the next season.
No NBA team has ever come back from a 3-0 deficit to win a best-of-seven series.
"Our mistakes we weren't able to overcome. Their high-level play, we weren't able to overcome either," Carlisle said. "It's really tough to go down 0-3. We're going to keep fighting. ... I like the way we're battling, but we've had bad shooting nights and horrible decision-making."
Oklahoma City had a 16-7 lead less than 5 minutes into the game, after Durant's alley-oop pass to Ibaka for a layup. The Thunder pushed ahead with 16-5 runs in both the second and third quarters, the later one clinching the game.
When Kendrick Perkins had a tip-in of Harden's miss with 4 minutes left in the first quarter, coach Rick Carlisle was so irate that the field goal wasn't disallowed for basket interference that he had to be restrained by one of his assistant coaches.
Carlisle went ballistic, charging onto the court screaming and pointing at official Marc Davis. Replays showed Carlisle might have had a good argument, but he got called for a technical foul and Westbrook's free throw put the Thunder up 21-11, their first double-digit lead.
"There's been frustration with officials, but we're not going to make it about officials," Carlisle said.
A couple of minutes later, Durant made his third 3-pointer of the first quarter to stretch the gap to 28-13.
Durant had 15 points by the end of the first quarter, but the Mavericks cut their deficit to 32-26. Vince Carter made two free throws, had a driving one-handed dunk and ended the quarter with a 3-pointer in the final 1:34 for Dallas.
After Dallas got within 32-28 on two free throws by Delonte West to start the second quarter, the Thunder were again up by 15 after consecutive 3-pointers by Fisher and Westbrook.
Harden made a cross-court pass to Fisher in the left corner in front of the Oklahoma City bench. Then after a wide-open Shawn Marion fumbled the ball out of bounds under the Dallas basket, Westbrook hit a 3-pointer for a 48-33 lead that led to a timeout by Carlisle.
Dallas got a slam from Ian Mahinmi and a driving layup by Kidd in the opening minute of the third quarter to get within 50-45.
But the Thunder then had their second 16-5 run, and was back up 66-50 when Thabo Sefolosha made a 3-pointer with 5:54 left in the quarter. The Mavericks never got closer than 11 points after that, finishing the third quarter only 4-of-18 shooting with four turnovers.
During a timeout with just under 8 minutes left in the game, Dallas fans started streaming out of the American Airlines Center.
Three minutes later, both coaches cleared their benches and got all the starters off the court.
Notes: Harden was added earlier Thursday to the list of finalists for the 2012 USA Basketball National Team. Thunder teammates Durant and Westbrook are also finalists for the 12-man U.S. Olympic team roster that will be announced later this year. "It says a lot about his development," Brooks said of Harden. "He represents himself in a very classy way, plays hard and does a lot of great things to help the team win. They recognized that." ... Dallas was assessed four technical fouls. Nowitzki got called for one in the first quarter, and West was called in the third quarter when he reached out and grabbed the wrist of official Greg Willard when questioning a call. There was a double technical early in the fourth against Brian Cardinal and Durant.