BOSTON — Coach Doc Rivers vowed he wouldn't change the way the Celtics did anything on defense in the NBA finals.

And why should he? Boston's defense was too good for Los Angeles in the regular season, and it still is so far in the postseason.

The Celtics shook off a poor defensive effort in the first half to contain Kobe Bryant and his sidekicks in the second half, pulling away for a 98-88 victory in Game 1 on Thursday night.

"In the second half, we did our jobs," Rivers said. "We got back on defense for the most part, we contested shots. I mean, that's how we have to play."

Bryant and the Lakers had been rolling offensively in the postseason, averaging 105.9 points while winning 12 of 15 games. Rivers had been asked what kinds of defensive adjustments the Celtics needed to make.

"We don't change as much as people think we do," Rivers said before the game. "That's fine that everyone thinks we do. But we've been pretty much a solid defensive team all year. We're not going to recreate the wheel tonight. We're going to play Celtic defense the way we've played all year."

That defense limited opponents to an NBA-low 41.9 percent, but it took the Celtics a while to warm up on that end after a long layoff since the Eastern Conference finals.

Los Angeles shot 50 percent while building a 51-46 halftime lead, but the Celtics limited the Lakers to 13-of-39 (33 percent) the rest of the way and held them to 41.6 percent (32-of-77) for the game.

"We didn't play any in the first half," Rivers said. "We didn't get back in the first half. We gambled in the first half. We gave them uncontested shots in the first half."

Bryant needed to take 26 shots for his 24 points. Pau Gasol and Derek Fisher each scored 15 points, but they combined for only five in the second half after going for 25 in the first 24 minutes.

Los Angeles, which has been the top-shooting team in the postseason, had its lowest-scoring game of the playoffs.

"We just didn't do a good job of moving the ball in the second half," Lakers forward Lamar Odom said. "In this game, they played the right way just for a little bit longer than us."

The Celtics won the two regular-season meetings by a combined 32 points, limiting Bryant to 32.6 percent shooting. But both meetings came in late 2007, long before the Lakers acquired Gasol from Memphis, so the Lakers felt those games were meaningless.

Turns out, they were a perfect preview for Game 1.

The Celtics led 77-73 heading to the final period, and Los Angeles was still down only four after Sasha Vujacic's jumper with 6:53 remaining. But the Lakers managed only one more field goal the rest of the way, going 5-of-20 in the final 12 minutes.

Bryant was 1-of-6 for four points in the fourth.

"We threw numerous defenders at him," Boston's Paul Pierce said. "(James) Posey, Ray (Allen), myself, and just wanted to give him a different look. We're all different type of defenders."

Bryant seemed to think it was more a bad night, but he's now had three of them against the Celtics this season. His 9-of-26 effort gets added to the 6-of-25 clunker and 9-of-21 outing he had in previous losses this season against Boston.

"He's the biggest catalyst for us defensively for us to make sure that we cover every base on the defensive end. You just can't rest with him," Allen said.

"It's a great feeling to know that as a team we have pretty good concepts, team defense-wise. We went out there and did a job on him where we made him a little bit more uncomfortable than he would have liked otherwise."

Bryant believes he'll shake off the loss and expects to be better in Game 2 on Sunday night, saying the Lakers would move the ball better and get him better shots.

Perhaps he shouldn't be so sure. Even one of his teammates realizes the Celtics seem to have an answer for the MVP.

"He's so great at breaking down defenses off the dribble," Fisher said. "The Celtics' defense just doesn't allow that type of play."