Before Thursday, LeBron James had pretty much mastered every opponent on every court in the NBA.

The lone exception was Boston. Including four games of the 2008 playoffs, the Celtics had beaten Cleveland nine straight on the parquet. And after one quarter, the Celtics certainly appeared headed for No. 10 with a 31-21 lead. But that’s when the Cavaliers, and specifically James and teammate Mo Williams, said enough was enough.

James had 36 and Williams canned four of his five 3-pointers in the second half as the Cavs ran away from the Celtics, 108-88, at TD Garden.

Afterward, he spoke to the great play of his team in the second half, what it was like to finally win in Boston and picking up the slack for the injured Shaquille O’Neal.

At the half the Celtics lead 56-48. They shot 60 percent and held the Cavaliers to 43 percent shooting.

Rajon Rondo has 14 points and eight assists, while Ray Allen has 13 on 5-for-7 shooting and 3-for-3 from 3-point range. Kevin Garnett also had a big half with eight points and six rebounds. LeBron James leads all scorers with 21 points.

Doc Rivers played Rondo and Nate Robinson together in the backcourt for a significant stretch of the second quarter. The Cavalier guards presented an excellent opportunity for Rivers to try the alignment as Mo Williams and Delonte West don’t present matchup problems with their size. Robinson scored six quick points off jump shots on the pick and roll.

Shaquille O’Neal went to the locker room halfway through the second quarter. He will miss the rest of the game after suffering a thumb injury. Former Celtic Leon Powe made his season debut for the Cavaliers and received a standing ovation from the crowd. Powe had been rehabbing after knee surgery.

Doc Rivers hinted before Thursday’s game with Cleveland that he planned to employ several different defensive strategies on LeBron James, including using one of his best big defenders on the big guard.

With Paul Pierce out for the second straight game with a sprained thumb and Marquis Daniels weakened with flu-like symptoms, Rivers was forced to get creative to come up with ways to defend the 6-8 swingman.

“Tony [Allen]is the other guy right now, and then Marcus [Landry] maybe, Scal maybe, maybe Kevin [Garnett],” Rivers said. “We’ll find that out. We don’t know what Marquis can give us so we’ll just have to wait and see.”

Welcome to the Rajon Rondo show where the Celtics guard dominated the first quarter and led them to a 31-21 lead.

Rondo had a hand in all of the Celtics first 21 points. He scored 10 of them himself and assisted on the other five field goals as the C’s made 10 of their first 13 shots before a Cleveland timeout. He finished the quarter with 12 points and six assists.

Paul Pierce did not play (thumb, flu) and Doc Rivers suggested before the game that he could miss more time. The Celtics play the lowly Nets on Saturday and then don’t play again until Tuesday so there’s good chance to get him some rest. Marquis Daniels did play despite suffering from the flu. Daniels started in Pierce’s place and drew the assignment of guarding LeBron James.

James kept the Cavaliers in the game with 10 points.

Paul Pierce will miss his second straight game with a sprained right thumb while Marquis Daniels will start after missing Wednesday’s practice with flu-like symptoms. Doc Rivers made the announcement in his pre-game chat with reporters.

WALTHAM — It seems much longer than four months when last the Celtics played the Cavaliers on opening night in Cleveland.

And for both teams – who meet tonight at TD Garden at 8 p.m. – the perspective has changed.

The Celtics went into Quicken Loans Arena on Oct. 27 and came away with a 95-89 win and served notice that they were intent on reclaiming their perch atop the Eastern Conference with Paul Pierce, Kevin Garnett and Ray Allen back in full stride.

That night Pierce led a balanced attack with 23 points, overcoming a game-high 38 from LeBron James. But C’s coach Doc Rivers said beyond the final score, there’s not much to take from the result that night.

“Nah, they’re not the same team,” Rivers said. “We’re not the same team. We won. We can take that away from it but other than that, I think both teams have forgotten about that.”

Indeed. Since then, the two teams have taken different paths. The Cavs, after losing their first two and starting the season 3-3, have rebounded to claim the top spot in the East and the NBA at 44-14, despite a recent three-game skid.

[Click here to listen to Rivers explain how Cavaliers are different than opening night.]

The Celtics, who stood 23-5 following a Christmas Day win over Orlando, have battled injuries and inconsistency and stand 36-19, just ahead of fourth-place Atlanta by a game in the loss column.

Both teams made moves at the trading deadline to strengthen themselves. While the Celtics added firepower with Nate Robinson, Cleveland acquired more front court athleticism in Antawn Jamisoin, dealing away Zydrunas Ilgauskas. The Cavs lost their first three games following the trade with Jamison in the starting lineup before he scored 18 in Tuesday’s win over New Orleans.

“They are different, watching them on tape the last two games,” Rivers said. “The Jamison thing has changed them a little bit. It definitely makes it more difficult to guard them so we have to get ready for that.” Read the rest of this entry »

WALTHAM — The Celtics will likely be without Paul Pierce when they take on LeBron James and the Cleveland Cavaliers at TD Garden on Thursday night, according to Celtics coach Doc Rivers.

Pierce was kept out of practice on Wednesday to protect his injured right thumb while Marquis Daniels was sent home with flu-like symptoms.

“I’m not going to say definitely but most likely not [Thursday],” Rivers said. “We’ll just evaluate it day-to-day. I didn’t want him to take a chance of getting his thumb hit at all in practice so that if he did feel good [Thursday] but if not, we’ll just wait. We’re just going to go a game at a time with him.”

Asked if he were concerned that Pierce’s thumb was anything more than a sprain, Rivers said likely not. “I would know if it’s something else and it’s not,” he said.

Also missing practice on Wednesday was Daniels. “We sent Marquis home. He looked awful so we’ll see [Thursday] and if not I have no idea right now so we’ll figure it out,” Rivers said.