Oklahoma City -- Already without leading scorer Kevin Durant, Oklahoma City Thunder coach Billy Donovan almost had his breath taken away early in the first quarter against Philadelphia when star point guard Russell Westbrook appeared to tweak an ankle.

To make matters worse, the winless Sixers weren't laying down for the home team.

"I said 'Do you want to come out?' and he kind of nodded and then when I went to put someone in, he said 'No, no, I'm fine'," Donovan said. "After that, I didn't ask him any more about it."

Westbrook showed no ill effects, as he went up over the rim to snatch a defensive rebound moments later, but it took him another two quarters to get warmed up on the offensive end. That coincided with the Thunder finally pulling away from the young and energetic Sixers late in the third quarter on the way to a 102-85 win.

Philadelphia's last charge had brought the Sixers within 62-61 before Westbrook took over. He led the Thunder on a 9-0 run to end the third quarter, scoring three straight buckets, including one on a steal and dunk.

That helped the Thunder (6-3) end the third quarter with a 71-61 advantage, and they went on to wrap up their third straight win and 12th in a row over Philadelphia.

After starting out 3 of 14, Westbrook hit 5 of his last 8 shots including two 3-pointers on his way to a 21-point night and his second triple-double of the season. He added a career-high 17 rebounds and 11 assists while playing a game-high 35 minutes.

Donovan was most impressed with Westbrook's work on the defensive boards, which sparked the Thunder to 24 fast-break points.

"He created some offensive rebounds, but the defensive rebounds enabled us to get on the fast break and run and that was a positive," Donovan said.

"I learned over the summer whenever I rebound and start the break it's better for our team and it gives the opposing team problems when I am able to do that and push the break," Westbrook said. "That leads to easy points.

Philadelphia (0-9) took the game to Oklahoma City, jumping out to a 24-18 lead after the first quarter as forwards Nerlens Noel and Christian Wood each scored six points.

But Noel and rookie Jahlil Okafor struggled to score inside on against Thunder big men Serge Ibaka, who had seven blocked shots and Steven Adams, who added three.

Noel and Okafor combined to make 7 of 30 shots.

"I think our defense was great," said Westbrook, who also added three steals. "I think our bigs did a great job protecting the paint against their inside game."

Okafor, who came in averaging 20.6 points in his first eight NBA games, scored only six points on 3 of 18 shooting but was upbeat about what he considered a learning experience

"They're a really good front line," he said. "I just love competition. Tonight was great for me. A chance for me to have some self-improvement. I'm looking forward to the next game and try to play better than I did tonight, that's for sure."

Sixers coach Brett Brown was not surprised by his team's effort, which saw them go toe to toe with the much deeper Thunder through the first 30 minutes of the game.

"We came in and I thought competed a large majority of the game," Brown said.

Wood topped the Sixers with 15 points, and Noel had 13 points and 11 boards.

NOTES: Thunder F Kevin Durant missed the first of what is expected to be at least five games with a left hamstring strain. Prior to tonight, the Thunder had started the same starting lineup in the first eight games. ... In Durant's absence, Anthony Morrow got his first start of the season, making the most of it by scoring eight points in the first eight minutes. ... It has been almost seven years since the Sixers defeated the Thunder. Their last victory over Oklahoma City came on November 15, 2008 at home. ... Sixers PG T.J. McConnell leads all NBA rookies in assists. He entered tonight's game averaging 8.3 assists per contest, good for fifth in the league overall.