Yao sat at his locker with a bag of ice on his right knee after the game. He finished with 16 points, 11 rebounds, two blocks and five turnovers.
The Chinese center had just one practice since recovering from a broken bone under his knee. It showed.
"In the second quarter, third quarter, I was almost like a high school player," Yao said. "Sometimes, Cleveland would just steal the ball from my hand."
Yao airballed a left hook on the Rockets' first possession, but immediately got in the Cavaliers' way on the other end by blocking a shot.
Wearing a black brace on his right knee, Yao looked slow and out of synch on offense, letting a crisp pass tip off his hands and missing open shots.
"Uneven, which is to be expected," Rockets coach Jeff Van Gundy said. "But he's got to cut down on his turnovers. We can't play well if he goes right back to what he was doing before he got hurt, which is being a high turnover guy. It's impossible to have offensive rhythm."
LeBron James, whose popularity in China helped him top Yao in All-Star voting this year, scored more than 30 points for the fourth straight game. He had 32.
Yao, who played 27 minutes, helped spark the Rockets in the fourth quarter after they trailed by 14. He scored seven straight points and provided a presence inside that forced Cleveland to take outside shots.
But when Zydrunas Ilgauskas stole ball from Yao with less than two minutes left, Yao fell to the floor in a heap, reports AP.
Yao, who said he fell on his elbow to avoid landing on his right knee, got up with help from a trainer, hobbled off, but returned to the game.
"I can't wait for my next game," he said.