"They outplayed us," Brooks said. "That's the bottom line. They got too many offensive rebounds, and we turned the ball over too many times. They played more physically than us."
Brooks credited Utah for Oklahoma City's first loss in five games.
"... They just put their bodies on us," he said, "and we didn't react the way we should have reacted the way we always react. Tonight they just outplayed us."
Kevin Durant, who finished with 33 points, agreed with his coach.
"They kicked our ass," Durant said. "Offensive rebounding and open shots. They just kicked our ass. They outrebounded us and scored in the paint. We turned the ball over and just gave them the game."
Asked if the noisy crowd of 18,552 was a factor, Durant said, "Nah, it's not even as loud as an empty Oklahoma City arena."
Russell Westbrook scored 12 of his 22 points in the first eight minutes. But he finished with seven turnovers and was not an offensive factor in the second half.
"They made shots; we started off defensively a little slow," he said. "But we have nights like that. "
Westbrook is confident the Thunder will bounce back Thursday night, when they play host to LeBron James and the Miami Heat.
The game is a rematch of last year's NBA Finals, which Miami won in five games.
"I think we've been pretty consistent throughout the year," Westbrook said. "You're going to have nights like this. You just have to find a way to fight through it. Just focus back up defensively and everything will take care of yourself."