HOUSTON - LeBron James watched another open shot clang off the rim, then screamed as he turned and trotted down the court. It was that kind of night for the Cleveland Cavaliers -- so bad, it almost ended up in the record books.

Yao Ming scored 24 points and the Houston Rockets overcame a mild concussion to Tracy McGrady to beat the cold-shooting Cavs 81-63 on Saturday night.

James scored 21, but was 7-for-22 from the field. Cleveland shot 28 percent (22-for-78) as a team, flirting with its all-time worst shooting performance (23.8 percent), set in 1970.

The Cavaliers' point total was just four points ahead of their all-time low for a game (59), set in 1997 against San Antonio.

"You shoot 28 percent from the field, you don't have a chance to win," said James.

The Rockets' offense was only slightly better after McGrady took an inadvertent elbow from Dikembe Mutombo in the first quarter and did not return.

Trainer Keith Jones said after the game that McGrady was fine and didn't have to go to the hospital. Jones said McGrady would be re-evaluated on Sunday. The Rockets' next game is Tuesday against Golden State.

"He went home and he's feeling pretty good," said Jones. "Tomorrow, I think he's going to feel a lot better."

Luther Head hit three 3-pointers and scored 13 for the Rockets, who've won five of their last six games and five in a a row at home. Rafer Alston added 10 points and four assists and Juwan Howard grabbed a season-high 13 rebounds.

The Rockets outrebounded Cleveland 55-41, the 12th time in 16 games that Houston has won the battle of the boards.

The Cavaliers, meanwhile, failed to reach 20 points in any quarter. They mustered a meager 10 in the second quarter after missing their last 14 shots of the first half.

Cleveland coach Mike Brown praised Houston for shutting down the Cavs. After all, the Rockets came into the game with the league's top scoring defense (89 points per game).

"They keep scrambling, they keep doing what they need to do to put themselves in position defensively to win the ballgame," he said.

James said the Cavs should take more of the blame.

"Most of the shots we missed were good looks or shots we usually make," he said.

The Rockets built a 20-11 lead in the first quarter after James missed five of his first six shots with Shane Battier guarding him.

When Battier went to the bench for a rest, McGrady took his turn defending James.

McGrady got hit with Mutombo's left elbow and hit the floor as James made a drive from the corner. McGrady lied still for a minute, then got up with his hand over his face and left the game with 1:13 left in the first quarter.

During a play stoppage, James walked toward the Rockets bench and asked Houston trainer Keith Jones about McGrady's condition.

A few minutes later, McGrady tried to walk to the locker room, but looked disoriented and staggered back to the bench. Rockets forward Steve Novak and Jones eventually helped McGrady slowly walk to the locker room.

Mutombo felt guilty about the accidental blow and apologized to McGrady at halftime. McGrady reassured Mutombo by saying he felt better.

"Then, I was able to smile," said Mutombo.

The Rockets led 23-15 when McGrady went out and built the lead to 43-29 by the break. James went 3-for-11 in the first half and the rest of the Cavs went 7-for-27.

Yao, meanwhile, had 20 points at halftime. He also had three blocks in the first half to reach 585 in his career and tie Ralph Sampson for third on the Rockets' all-time list. He got one more block in the second half to pass Sampson.

Head and Alston hit 3-pointers in the first 90 seconds of the third quarter, part of a 10-2 Rockets run that extended the lead to 53-31.

The Cavaliers answered with a 10-2 spurt as the Rockets started shooting poorly, going 6 minutes without a field goal.

But after a Houston time out, Battier ended the drought with a post move and a 3-pointer that pushed the Rockets' lead to 60-41.

The Cavs got within 14 in the fourth quarter, but never put together more than two straight baskets the rest of the way.