BOSTON — With titans Bill Russell and John Havlicek on hand for the occasion, the new Garden filled with chants of, "Beat L.A.! Beat L.A.!" in the moments before tipoff.

And so the Celtics clinched their 17th NBA title today in a manner consistent with their glorious past.

Dominant.

For the first time since 1986, order was restored to the basketball universe. And somewhere in that universe, Red Auerbach must have fired up a cigar.

With a relentless performance from Kevin Garnett — the cornerstone of the Celtics' revival from a 24-win team to NBA champions in one year — and another stifling defensive stand, the Celtics thrashed the Lakers, 131-92, in Game 6 to win the best-of-seven championship series, 4-2.

Where to begin on the list of redemptive powers that prevailed in a series that pitted these storied rivals who have totaled 31 of the 62 NBA titles? From Danny Ainge's bold moves to acquire Garnett and Ray Allen last summer, to the quirky but effective ownership group led by lifelong New England sports fan Wyc Grousbeck, to the steady Doc Rivers prevailing over Phil Jackson — it all somehow seemed to fit so neatly into Celtics lore.

Rivers not only guided Garnett, Allen, and long-suffering Celtic Paul Pierce to their first championship, but he denied Jackson the opportunity to pass Auerbach in the process. Jackson remains tied with the Celtics' legendary coach with nine championships.

Jackson won with Michael Jordan and Scottie Pippen in Chicago, and with Kobe Bryant and Shaquille O'Neal in L.A. But Bryant was not enough against the Celtics, who exceeded their reputation as the best defensive team in the league with a seamless display that must've made courtside patron Bill Belichick envious.

Auerbach, whose signature graced the parquet floor near midcourt, would've been proud of that. He would've embraced Pierce, the star of the series, Garnett, and Allen, too — not to mention role players like P.J. Brown, James Posey, Leon Powe, and Glen "Big Baby" Davis, whose quality minutes off the bench seemed cut from the old-time Celtics cloth.

Garnett had 26 points and 14 rebounds, Pierce added 17 points and 10 assists, and Allen overcame a family matter that kept him in Los Angeles for the past two days — plus a left eye injury in the first quarter — to contribute 26 points. Rajon Rondo added 21 points and eight assists. Not even a four-hour delay flying out of L.A. on Monday could derail the Celtics, who seemed pre-ordained champions from the opening tip of the season and endured seven-game scares from Atlanta and Cleveland in the first two rounds.

As important as the contributions from the Big Three was, the defensive mastery on Bryant, who managed only 22 points, shooting 7-for-22. Bryant, who won three titles with Shaq, went to the bench in the fourth quarter to chants of, "Where is Ko-be?" He scored 11 in the first quarter but only 11 the rest of the way in what became the biggest blowout in a clinching game in Finals history, eclipsing the Celtics' 33-point victory over the Lakers in 1965.

With the building pulsating with anticipation, Grousbeck was a nervous wreck on the floor during pregame festivities, fidgeting with his blazer sleeves and unwilling to project what his emotions might be in a few hours.

"I don't want to jinx it," Grousbeck said, betraying his roots as a homegrown New Englander.

The Celtics survived an early barrage from Bryant, who made three deep three-pointers in the first quarter. And Boston had to endure another injury scare when Allen, who'd spent the past two days tending to a family matter in Los Angeles, got poked in the eye by Lamar Odom with 4:30 left in the first quarter.

Allen stayed . . . and stayed . . . and stayed in the locker room, but finally re-emerged with about five minutes left in the second quarter after seeing an eye specialist. By the time he returned to the floor with 4:44 left in the half, his teammates had built a 12-point lead, 43-31. Bryant, who hit four of his first five shots from the field, missed his next seven and scored only three in the second quarter, when the Celtics started running away.

Posey's three-pointer made it 43-28 with 5:29 left in the quarter, but the signature play was Garnett's impersonation of George Gervin in the final minute of the half. With 47.3 seconds left, Garnett hung in the air palming the ball, absorbed a foul from Odom and kissed the ball one-handed off the glass for a three-point play that gave Boston a 56-35 lead. It was 58-35 at halftime on the strength of a 26-6 run to close the quarter.

The Celtics' suffocating defense — against Bryant and everyone else — held the Lakers to 8-for-27 shooting from the field in the half and 3-for-13 in the second quarter. The Celtics shrugged off Allen's injury and 2-for-9 shooting from Pierce in the first half because of contributions from reserves Posey, Eddie House, and Davis, who hadn't played a minute since logging 11 minutes in Game 4 of the conference finals against Detroit on May 26.