BOSTON — These aren't the same Celtics that LeBron James remembers from his last two playoff trips to Boston.


In Sunday’s Game 1 of the Eastern Conference finals, the best player in the world ran into a Celtics team ready and waiting for him.


After bulldozing his way to two lopsided playoff series victories in the last four seasons — including last year’s conference finals that featured three Cleveland Cavaliers routs on the parquet by a combined [...]

BOSTON — These aren't the same Celtics that LeBron James remembers from his last two playoff trips to Boston.

In Sunday’s Game 1 of the Eastern Conference finals, the best player in the world ran into a Celtics team ready and waiting for him.

After bulldozing his way to two lopsided playoff series victories in the last four seasons — including last year’s conference finals that featured three Cleveland Cavaliers routs on the parquet by a combined 93-point margin — James was held to 15 points on 5-of-16 shooting in a 108-83 drubbing on Sunday.

Game 2 is Tuesday night at TD Garden at 8:30 p.m.

“The last couple of playoff meetings between us here, they blew us out of the water,” said Celtics guard Marcus Smart. “We have a different team just like they do. And a lot of younger guys. So for them to see this, and have that feeling of winning like we did tonight, is huge.”

Marcus Morris moved into the starting lineup to guard James and put up 21 points and 10 rebounds, Jaylen Brown was dynamic with 23 points and eight rebounds in just 28 minutes, Al Horford hit his first seven shots on his way to 20 points in 27 minutes, Jayson Tatum had 16 points, and Terry Rozier had eight points, eight assists and six rebounds for Boston.

“Every game is a statement game,” Rozier said. “Especially with us, and what we have been through (with injuries this season)."

The Cavaliers shot just 36 percent and missed 22-of-26 3-pointers, while James committed seven turnovers and was a game-worst minus-32.

“Our whole lives we’ve been fighting bigger opponents than us,” Smart said, “playing LeBron and that kind of team. They’re here for a reason because of the talent they have.

"We have talent as well. We have guys who are fearless."

“We definitely feel good about this,” Tatum said, “but we understand that they are going to come out with a lot more intensity the next game, and we have to be ready to match that swing back.”

The Celtics set tone from the outset as they used a 25-2 run in the first quarter to build an 18-point lead, which they extended to as many as 28 in the second quarter. They led, 61-35, at halftime.

“It was our energy defensively,” Horford said. “I think we really fed off our crowd. Then on offense we were taking good shots, really moving the ball, and really taking really good looks. That helped. And we were knocking them down.”

The Celtics cooled off in the third quarter as the Cavaliers slowly closed the gap.

Boston was still up by 23 after a Brown 3-pointer with 4:13 left in the quarter, but the Cavaliers took a 12-3 run into the end of the quarter as Jeff Green’s second-chance shot beat the buzzer for a 78-64 gap through three.

The Celtics then opened the fourth quarter on a 7-0 run with a Morris put-back slam, a Smart 3-pointer and a Tatum coast-to-coast drive, putting them up by 21 with 10:51 to play. The Cavaliers scored the next four before Smart scored inside, James committed his seventh turnover of the game and Tatum followed with a basket.

“Having the poise to say that they’re going to make some runs,” Celtics coach Brad Stevens said, “they’re going to make some plays, but just focus on the next one, is going to be important the rest of the way. It’s something I don’t think we did as well with last year, and hopefully we can play a little bit better (in this series) when they do go on the runs.”

A pair of Morris free throws and a Tatum 3-pointer put the Celtics up, 94-68, with 7:47 to play before a Rozier drive capped an 11-0 knockout run for a 96-68 gap. James exited with 7:09 to go.

A Rozier 3-pointer and a Morris 3-pointer made it a 101-72 game with 5:14 on the clock as Stevens emptied the bench to the extent that he could with 11 healthy players.

"I thought our guys were locked in," Stevens said. "We're just going to have to be that again on Tuesday night."