BOSTON – It was a dream end to a dream season. The Boston Celtics, who finished last in the Eastern Conference a year ago, are NBA champions after thrashing the Los Angeles Lakers 131-92 Tuesday night to win the best-of-seven series, four games to two.

If this were a boxing match, it would have been stopped in the second round. Boston hammered the Lakers with a crushing 26-6 run to close the first half, limiting L.A. to one basket in the final 7:32 of the quarter, to open up a gaping 58-35 lead at halftime.

RELATED: Celtics Crush Lakers, 131-92, for NBA Championship

It was a career-defining game for Boston’s Kevin Garnett in particular. Derided as a playoff failure for much of his career, Garnett dominated the first half of the most important game of his career after saying he had played “like trash” in a Game 5 defeat. By the break he had 17 points on 8-of-12 shooting — as many field goals as the entire Laker team — and capped it off with a one-handed dipsy-do around Lamar Odom to get a basket and foul, sending the already frenetic crowd into hysterics.

Garnett finished with 26 points and a game-high 14 rebounds; of more importance, the league’s Defensive Player of the Year added a championship ring that cements his legacy as one of the all-time great power forwards. Series MVP Paul Pierce added 17 points and 10 assists, while the third member of Boston’s “Big Three,” Ray Allen, tied Garnett with a game-high 26 – including seven 3-pointers.

They got help from the supporting cast, too. Point guard Rajon Rondo shook off an ankle sprain to chip in 21 points, eight rebounds, seven assists, and six of Boston’s NBA Finals-record 18 steals. Subs James Posey and Eddie House added 13 points in the first three quarters as Boston built a 29-point lead.

But the story for the Celtics was the same one it had been all season – defense. Once again, the Lakers struggled to score against the tough, physical Celtics defense. L.A. only mustered 15 points in that fateful second quarter, and 35 for the half – one in which they had more turnovers (11) than baskets (8) and failed to grab a single offensive rebound.

League MVP Kobe Bryant scored 22 points but was held to 7-of-21 shooting and had four turnovers against one assist. For the series he scored 25.7 points per game, but Boston held him to 41.4% shooting.

That effort against Bryant was par for the course for the Celtics’ season. The Celtics won 66 regular season games, thanks to one of the best defensive squads of all time, and kept up the suffocating D in the playoffs.

Pierce earned MVP honors as much for his defense as his offense. He faced off against Bryant at both ends and, shockingly, got the better of the match-up, consistently forcing him into contested jumpers. Offensively, Pierce repeatedly beat L.A. on drives to the basket and averaged 21.8 points for the series. Even more impressive, he did this despite injuring his knee in the first half of Game 1.

Boston’s win was the culmination of the greatest turnaround in league history. A 24-win team a year ago, the Celtics traded for All-Stars Garnett and Allen in the off-season and added veterans James Posey, Eddie House, Sam Cassell, and P.J. Brown. With Pierce healthy after an injury-riddled 2006-07 campaign, the Celtics were an immediate juggernaut.

The determination of Pierce, Allen and Garnett — three veterans who had tasted plenty of individual success but never played in a Finals game before this season — was palpable all year, and especially in these Finals. Boston repeatedly beat the Lakers to loose balls, outmuscled them the paint, and did all the little things — taking charges, setting picks, fouling strategically — that define champions.

They also refused to give up, shaking off numerous injuries throughout the series and coming back from 24 points down to steal Game 4 in Los Angeles and set up Tuesday’s coronation.

Finally, the victory was also a huge vindication for Boston coach Doc Rivers. Skewered as the Celtics struggled a year ago, and heavily questioned even in the early rounds of the playoffs, he outfoxed the Lakers’ legendary Phil Jackson to put Boston in position to win the crown. No maneuver was more impactful than his switch to a smaller, floor-spacing lineup in Game 4 that featured House and Posey alongside his three stars.

Los Angeles also can look back with fondness on its season — one that began with Bryant demanding a trade and many pundits wondering if the team would even make the playoffs.

Instead the club’s young core came together, a midseason trade for Pau Gasol energized it further, and Bryant finally began to understand the difference between being a great player and being a great teammate. With injured center Andrew Bynum due to return, they’ll likely begin next year as the favorites to win the title.

Nonetheless, this was the Celtics’ night, and the Celtics’ year. And as Garnett, Allen and Pierce checked out with 4:04 left and joined in a group hug with Rivers, chants of “seventeen” started — for the Celtics’ 17th championship — and a long night of partying kicked off in Boston.