"Obviously, when you lose a guy of that caliber, they've got a guy they can counter with with Kanter, who's a really good low-post scorer," Houston interim coach J.B. Bickerstaff said. "With Dwight in there, we can shut that down. He can guard guys one-on-one in the post. Kanter was able to get it going a little bit after Dwight went out."
Kevin Durant had 33 points and 12 rebounds for the Thunder, who have won 10 of 11 and six straight at home.
James Harden had 33 points, seven rebounds and seven assists, but he made just 2 of 10 field goals in the second half. Corey Brewer added 17 points for the Rockets, who shot 38 percent overall and made just 9 of 39 3-pointers and 27 of 43 free throws.
"They want to shoot threes and get layups, and I think we closed all of that off tonight," Durant said. "We were there on the catch for them guys and we didn't just let them play freely. When we do that, we're a scary team."
Bickerstaff said shots simply weren't falling.
"We've got to take those shots with confidence and we believe in the guys that are taking those shots," he said. "Tonight they didn't go. The past few weeks they've been falling and they'll go again. Guys work on it. They've got to trust their training, shoot them with confidence and we'll get them."
The Rockets led 58-55 at halftime. They led by as many as 12 points in the second quarter, but Howard made just 2 of 9 free throws in the period to help the Thunder creep back into the game.
Howard was ejected with 7:06 left in the third quarter -- Bickerstaff said after the game he was told it was for something Howard said. The Thunder finally took the lead on a putback by Kanter, and a dunk by Durant on an assist from Westbrook put Oklahoma City ahead 80-76. The Thunder led 89-83 at the end of the third quarter.
Westbrook got his triple-double on an assist to Kyle Singler, who scored and was fouled. Singler's free throw put Oklahoma City ahead 101-92.
Howard missed 11 free throws in the game, despite leaving early. DeAndre Jordan of the Los Angeles Clippers and Andre Drummond of the Detroit Pistons are the only players in the league to have missed more than 11 free throws in any game this season. Drummond has done it three times and Jordan twice.
Kanter on Thunder's emphasis on defense: "We've been talking about it this morning, the day before, the day before and the day before, we've been talking about defense."
Oklahoma City improved to 21-4 all-time when Westbrook gets a triple-double.
Rockets: Harden, a former Thunder player, was booed loudly during pregame introductions. ... Howard's first technical came after he put Singler in a headlock during a battle for a rebound in the second quarter. ... Howard finished with eight points and eight rebounds in 21 minutes.
Thunder: Houston Astros pitcher Dallas Keuchel was in the crowd. He is from Tulsa, Oklahoma. ... Cameron Payne (concussion) and Andre Roberson (right knee sprain) did not play. ... Dion Waiters, who started in Roberson's place, got a technical in the final seconds of the third quarter. He finished with 16 points. ... Oklahoma City scored at least 100 points for the seventh straight game. ... Steven Adams and Kanter each had 10 rebounds.