Celtics' early burst leads to Game 1 rout of LeBron and the Cavs

Horford and Brown ignite Celtics' laugher (0:58)

Al Horford and Jaylen Brown combined for 43 points on 17-of-26 shooting in Boston's Game 1 win. (0:58)

BOSTON -- As LeBron James waited to inbound the ball late in the first half of Sunday's Game 1 of the Eastern Conference finals, a single piece of green confetti danced toward him.

It was not a premature celebration for a Boston Celtics team building what would be a 26-point halftime lead -- the worst postseason deficit ever endured by a James-led team -- nor was it a troll of the Philadelphia 76ers and their Game 3 snafu last round.

The confetti, though -- merely leftover from a concert Saturday night at TD Garden -- was foretelling of the Game 1 dismantling the Celtics would put on the defending Eastern Conference champs.

These fearless young Celtics swore they wouldn't be overwhelmed by having to play against James amid his run of East supremacy. True to their word, the Celtics blitzed the Cleveland Cavaliers with a monster first-half run and then cruised to a 108-83 triumph.

It was 21-year-old Jaylen Brown who scored a team-high 23 points, while veteran leader Al Horford added 20. Jayson Tatum overcame a quiet start to add 16 points, though it ended his Celtics rookie record of seven straight games with 20 points or more in the postseason.

James struggled all afternoon as Boston sent a variety of bodies his way, including Marcus Morris, who moved into a starting role the day after proudly declaring himself one of the best James defenders in the NBA.

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James finished with 15 points on 5-for-16 shooting and was 0-for-5 from 3-point range. He was minus-26 in the first half -- the worst plus/minus of his postseason career -- and minus-32 overall.

With injured stars Kyrie Irving and Gordon Hayward watching from the end of the Boston bench, the Celtics hit the Cavaliers with a 17-0 first-quarter run then stretched their lead as high as 21 in the frame. Horford and Brown paired up for 24 of Boston's 36 points as the Celtics shot 63.6 percent during the quarter.

Boston's run ended up being a 25-2 burst overall in which Boston connected on 10 of 15 field goals, all while the Cavs made just 1 of 12 shots over a 7½-minute span.

The Celtics draped every seat with black "Protect The Parquet" shirts for Game 1 and the Celtics improved to 8-0 here this postseason. Game 2 will be at TD Garden on Tuesday night.

In the buildup to Game 1, the Celtics were peppered with questions about having to go against James and the team that dominated a very different-looking Boston squad in a five-game East finals a year ago.

Celtics players repeatedly said they were embracing the challenge and the notion that they were again big underdogs.

Before Sunday's game, Celtics coach Brad Stevens said the challenge of trying to get past James was good for his team.

"At the end of the day, we'd rather be playing and him be in our path, right? I mean, we get a chance to compete against the best player of this generation, and that is pretty special," Stevens said.

"And our guys look forward to it. But we can't be focused on LeBron versus the Celtics."