OKLAHOMA CITY (AP) -- Here's a new twist on the Oklahoma City Thunder's budding rivalry with the Dallas Mavericks: With a game coming down to crunch time, Dirk Nowitzki didn't want the ball.

Instead, it was Russell Westbrook who shrugged off a shaky start and closed out a Thunder victory. Kevin Durant scored 40 points while Westbrook added eight of his 16 points in overtime to help Oklahoma City beat Dallas 111-105 on Thursday night for their 11th straight win at home.

Westbrook turned the game around with six straight points after the Mavs had gone up 104-101 on Chris Kaman's bucket inside midway through overtime. Westbrook had a layup, hit a jumper over the rusty Nowitzki and then made a leaping steal of an O.J. Mayo pass that led to a fast-break layup. The sequence left Mavericks owner Mark Cuban shaking his head in his seat near the team's bench.

"I just try to make an impact on the game," said Westbrook, who also had 10 assists, six rebounds and three steals. "Maybe it's not scoring. Maybe it's rebounding, maybe it's passing, maybe it's defending. "But I just try to make an impact on the game every night."

Until the end, it had been Westbrook who was frustrated. He missed eight of his first 10 shots and struggled to contain ex-UCLA teammate Darren Collison, who scored a season-high 32 points and hit a desperation 3-pointer at the buzzer to force overtime.

"Sometimes there's nights like that," Westbrook said. "You've just got to continue to play, fight through it and play your game."

When asked specifically about Collison, Westbrook cut off his postgame interview and cussed on his way out of the locker room.

"He kept fighting and kept fighting for the team,"Thunder coach Scott Brooks said. " ... I love Russell. I love what he does. I love what he's about. He competes every time. He's a big part of why we're a good team."

Still working his way back into shape, Nowitzki proved to be a liability during Oklahoma City's 17-6 fourth-quarter comeback. He sagged off of Durant far enough that the three-time NBA scoring champion could drill a 3-pointer from the left wing, then was trailing a play when Mayo backed into him and lost the ball to set up Durant's fast-break dunk and three-point play.

"I don't really have the stamina or the legs there, so I couldn't really put on the brakes. I mean, I kicked the ball out of his hands," Nowitzki said. "It was just some ugly stuff."

In overtime, Carlisle pulled Nowitzki in favor of Shawn Marion for defense at one point. And he wasn't his usual clutch self with the game on the line - as Oklahoma City knows well from the Western Conference finals two seasons ago.

"I didn't really want the ball that much," Nowitzki said. "I don't really feel like I've got the stamina, the lift to do something out there with the ball, make a one-on-one move.

"I think that I'm a week or two away of really dominating the ball down the stretch and making some stuff happen."

Nowitzki said his knee feels "phenomenal," going as far as saying he thinks the surgery will be good for the rest of his career, but at this point his legs feel heavy.

"I don't really have any bounce or lift,'' Nowitzki said. ''I don't really have that bounce in my step yet, but I'll keep working. As long as the knee respondes the right way, I think my legs will come back sooner or later."

Serge Ibaka added 19 points and matched his season high with 17 rebounds as Oklahoma City charged back from 10 points down in the final 7:17 of regulation and found a way to win after losing back-to-back games for the first time this season.

After Westbrook put Oklahoma City up 107-104, Mayo was fouled on Dallas' next possession while shooting a 3-pointer. He missed the first two foul shots with 33 seconds left as the sold-out Chesapeake Energy Arena crowd roared louder with each miss.

Westbrook hit two free throws after that to put it away - this time for good. Collison came up with a desperation 3-pointer at the buzzer to send it to overtime after Dallas had given up the lead for the first time since the opening 4 minutes.

Marion inbounded from the sideline with 2.2 seconds left, collected a deflected pass and headed toward the lane before kicking the ball out to Collison, who caught the ball in mid-air and heaved it toward the basket for the tying 3 from the right wing.

Replays showed he released the shot with one-tenth of a second left on the clock.

"He was phenomenal for us tonight and fun to watch. I hate to waste an effort like that from him obviously," said Nowitzki, who had nine points in his second game back after offseason knee surgery.

"We definitely need him to keep playing like that. Obviously, he's not going to score 30 every night but we need him to attack and make some stuff happen."

Kaman ended up with 17 points and Marion chipped in 14 points and nine rebounds for the Mavericks, who were swept on a treacherous three-game road trip that featured stops at West contenders Memphis, San Antonio and Oklahoma City despite getting Nowitzki back. Dallas has lost seven of eight to fall to 12-17.

"I think the goal is still the playoffs. I don't think that's going to change," Nowitzki said.

Dallas had been 11-1 this season when leading at the beginning of the fourth quarter and 11-2 after holding a 10-point lead or larger. Mayo, who had been averaging 20.6 points, scored only four and has 29 total over the last four games.

Oklahoma City had won 12 in a row before losing back-to-back games at Minnesota and Miami.

The franchises have grown quite familiar over the past two seasons, with each team taking a turn knocking the other out of the playoffs - in addition to their proximity along Interstate 35 and a handful of preseason matchups to go with the usual regular-season meetings. Dallas eliminated Oklahoma City in the Western Conference finals before winning the NBA title in 2011 and the Thunder swept the Mavs in the first round last season.

Other than Nowitzki and coach Rick Carlisle, there aren't many remnants of those Dallas teams left. An offseason overhaul left Marion, Vince Carter, Brandan Wright and Rodrigue Beaubois as the only Mavericks remaining from those clashes.

Notes: Beaubois, a reserve guard for the Mavericks, did not play because of an illness. Carlisle said he hoped to have Beaubois back for Friday's home game against Denver. ... Reggie Jackson took Eric Maynor's minutes as Westbrook's backup at point guard for the second straight game. ... Durant remained first among Western Conference frontcourt players in NBA All-Star balloting returns announced Thursday. Westbrook stayed in fifth among guards. Nowitzki, who has made 11 straight All-Star games, was 13th in the frontcourt. ... Ibaka had a double-double by halftime for the first time in his career.