What's the difference? For Rockets, plenty

These weren't the Houston Rockets of November. The defense was stronger, Yao Ming's play was more dominant, and the Celtics were left scrambling for answers that never came.

Much of the damage in last night's 89-85 Rockets stunner was done in the paint as Houston outscored the Celtics, 36-18. Yao scored a team-high 26 points, dropping 10 of 13 from the floor and adding 6 of 9 from the free throw line. There wasn't a comparable answer for the Celtics, who defeated Houston, 103-99, Nov. 4.

For nearly 37 minutes, Yao toughed it out against the Celtics' big men and came out ahead, grabbing eight rebounds. Rockets coach Rick Adelman said the goal was to force the Celtics' Big Three - Kevin Garnett, Paul Pierce, and Ray Allen - into taking jump shots.

"We didn't want to have them get the ball where they could get layups," Adelman said. "They really hurt us in Houston on the boards, and whenever they missed, they got it back and they scored. They just kind of pushed us around, so we made a conscious effort of talking about that, so it's something we had to do."

These weren't the same Celtics who dominated Houston in their last meeting. Kendrick Perkins was 7 of 8 from the floor and scored 15 points in 34:53 in that outing. The Celtics picked up 42 points in the paint, compared with 26 for the Rockets.

The situation was reversed last night.

"I think they made the extra pass," Perkins said. "They got into the paint. They played great defense. Their defense was way better than it was the last time that we played."

Perkins got into foul trouble early and was held scoreless and had three rebounds. Early in the third quarter, he was on the bench with four fouls. He took just one shot, but that was not what bothered him about his play.

"Some nights it's going to be like that," he said. "Some nights I might get one [shot]. Some nights I might get 12. That's not my role on the team, to take shots. My role on the team is to play defense and rebound, so I just didn't do a good job of that. There's a lot of things that you could blame throughout the game that if we had done them better, we probably could have won the game."

As the Celtics reflected on their fourth loss in five games, the conversation returned to the play of Yao, who was held to 8 points (4-of-14 shooting) in the last meeting just four games into the season.

"Oh man, he was tough, real tough," Leon Powe said. "That's a very skilled big man. Man, he was real tough down low in the box."

Powe went on to describe Yao's ability to move his jump hook and his effectiveness on the boards.

"It's a very difficult matchup for anybody," he said.

When Perkins encountered foul trouble, it presented a chance for Glen Davis, who led the Boston reserves with 12 points in 22:46.

"I think they played a great game," Davis said. "We competed to a certain level and I think we played good in stretches, but they were more consistent."

As the Celtics prepare to visit Cleveland tomorrow, Perkins hopes the defensive struggles will not weigh on them.

"Right now, the biggest thing is that we stick together and just stay positive," he said. "When things go bad, teams tend to separate, but when we won 19 in a row, everything was all good. So the biggest thing for us right now is just to stick together."

Monique Walker can be reached at mwalker@globe.com.