Pierce made two crucial jumpers and two free throws in the final 1:03 to pace the Celtics , whose drive to a second straight title was derailed when Garnett injured his knee late last season. Rasheed Wallace, added as a free agent during the offseason, had 12 points.

James scored 38 and O'Neal added 10 points and 10 rebounds for the Cavaliers, who won their first 23 home games last season but are already 0-1 on their floor.

Because of the 14-time All-Star O'Neal's addition, the Cavaliers have gotten the bulk of the preseason attention and are a trendy pick to win their first NBA title.

The Celtics may have other plans.

Garnett looked fully recovered from surgery to repair his right knee. Allen stroked a couple 3s, and Pierce was his cold-blooded best down the stretch. After James missed a 3-pointer that would have brought Cleveland within one, Pierce stuck a 15-footer to make it 89-83.

Cleveland turned it over when newly acquired Anthony Parker couldn't handle a pass from James, and Pierce made the Cavs pay again with a second dagger from the outside.

Pierce had 11 rebounds, Garnett 10 and Rajon Rondo added 10 assists for Boston.

James was in MVP form, but this wasn't the debut the Cavs envisioned. Their offense sputtered as coach Mike Brown feared, and their defense didn't do a good job on the perimeter and was missing one of its key components, guard Delonte West, who was inactive for the game and whose future seems uncertain in Cleveland.

The Cavaliers began their quest for a title without the troubled but valuable West, who has had a turbulent offseason dealing with medical and personal issues. General manager Danny Ferry and a support team helping the guard decided West was not ready to play.

West has bipolar disorder and blamed an arrest last month on weapons charges near his home in Maryland on not staying with his medications. As the Cavs were introduced before the game, West leaned against a wall in the tunnel leading to Cleveland's locker room.

The circus-like atmosphere outside the arena was more befitting an NBA finals game in June than an October opener. Cleveland fans have been waiting months for this night, the tip-off to a season already unlike any in the franchise's 40-year history.

On the other side of Ontario Street, a billboard said, "It Begins." What matters to the Cavs, though, is how it ends.

James finished with eight assists, made four 3-poiners and delivered two spectacular chase-down blocks.

Wearing a pair of headphones with blue Yankees pinstripes and NY logo, James, who can become a free agent after the season, stretched out before the game in the locker room listening to Young Jeezy's "24, 23," a song that includes lyrics about Los Angeles Lakers superstar Kobe Bryant and James.

"I used to play Kobe, but now I play LeBron," James rapped loudly while eyeing a flat-screen TV.

He wasn't singing afterward.

The Cavaliers came out intent on running the Celtics out as they did late last season in a 31-point win at home.

Cleveland broke out to a 13-2 lead, went up 19-5 on a short jumper by O'Neal and led 28-21 after one. The Cavs' defensive highlight of the period -- and maybe one for the season -- came when James chased down the speedy Rondo and rejected his dunk attempt.

But as happened so many times in the past, the Cavs' offense bogged down when James went to the bench and the Celtics heated up. Allen made two 3-pointers and scored 11 in the second quarter and the Celtics made seven 3s while opening a 51-45 halftime lead.

James had a basket taken away when the officials reviewed a layup in the final minute. It was the first use of the NBA's expanded instant-replay system, which allows officials to check to see if a shot has gotten off before the 24-second shot clock expires.