BOSTON — Hours before Tuesday’s tipoff, Darius Garland boasted that the Cavs were going to shock the world.

Maybe they still will. But not in Game 1.

Cleveland lost the Eastern Conference semifinals opener to the heavily favored Boston Celtics, 120-95 — a game that featured just two lead changes and two ties, with the East’s top seed leading for 46 minutes.

“They’re a good team,” said Max Strus, who is playing the Celtics for a third consecutive postseason. “But we are too. We will bounce back. Come back and be ready for Game 2. It’s the little things. We have to do the little things better. Room for growth. Things we can change probably.”

On the heels of their first playoff series win without LeBron James since 1993 — a milestone moment for the franchise — the Cavs knew plenty was stacked against them. They entered this second-round matchup with the longest odds to win a series in the conference semis or beyond since 2017. Star guard Donovan Mitchell even talked about everyone picking Boston to win.

Tuesday night spotlighted why.

Playing inside famed TD Garden, it took the Cavs a few minutes to settle in. They were down by double digits less than three minutes into the game. But Cleveland regained its composure, taking its first — and only — lead at the 5:32 mark of the first quarter.

That lasted 18 seconds.

It was all Boston after that. With the raucous crowd in a sea of green, white and black behind them, the Celtics pushed their advantage to a game-high 26 at the 3:42 mark of the fourth quarter. That’s when Cavs coach J.B. Bickerstaff raised the white flag.

Out-played. Out-competed. Out-classed.

Too much talent. Too much firepower. Too much versatility. Inside. Outside. The Celtics looked the part of title favorites.

“It is a different game, especially for us defensively with what we’re trying to do and what we’re defending,” Bickerstaff said. “You go from a team that didn’t shoot a ton of 3s to a team that wants to shoot a whole bunch of 3s. It’ll take us a little bit of time to just kind of adjust. I think tonight was that night.”

Boston went 45 of 92 (48.9%) from the field and 18 of 46 (39.1%) from 3-point range while committing just nine turnovers. Even though there were moments when the Cavs seemed free from the Orlando first-round stranglehold, with more space on the perimeter, they failed to crack the 100-point mark for the sixth time in these playoffs, shooting just 41.1% overall, including 26.2% from beyond the arc.

“Have to continue to run our offense and the biggest thing is we have to hit shots,” Mitchell said. “It’s one game. We will be better at it. Sucks that we lost but good to see where we can improve at. Upset we lost but not overreacting. Different series. Different group. Different ways to score. Different things we can learn.”

Mitchell carried over his stellar play from round one. He finished with 33 points on 12 of 25 shooting and 4 of 11 from beyond the arc to go with six rebounds and five assists in 37 minutes. He now has as many 30-point postseason games as LeBron James and Jayson Tatum since entering the NBA. The Cavs were outscored 17-6 in the non-Mitchell minutes of consequence, including a forceful 10-2 Boston run to open the fourth quarter — a stretch in which they took complete control.

“Picking my spots,” Mitchell explained. “Trying to find ways to continue to be aggressive. Understanding that I’m going to need to score the ball, especially in the in the series. I can be better, and I will.”

Evan Mobley, starting in place of injured Jarrett Allen who missed his fourth straight playoff game because of a bruised rib, finished with 17 points and 13 boards. Mobley made his final seven shots after a poor start. Garland chipped in with 14 points in 36 minutes. He also left the arena with a cut above his eye following a second-half collision. Isaac Okoro, joining the starting quintet once again, had 11 points, eight of which came in the first quarter as the Celtics repeatedly helped off him and dared him to take jumpers.

Strus, the prized offseason pickup, brought in to add a different offensive dimension, tallied five points, going 2 of 8 shooting and 1 of 5 from deep in 35 minutes.

The Celtics were led by swingman Jaylen Brown, who set the tone with nine of Boston’s first 12 points before finishing with a team-high 32. Derrick White added 25, going 9 of 16 from the field and 7 of 12 on 3s. Tatum, the MVP candidate, tallied 18 points and 11 boards.

The Cavs, who have yet to win a road game in these playoffs, entered Tuesday night hoping to steal one. Maybe the Celtics would be rusty after so much time off. Maybe the Cavs would be better offensively while not dealing with the supersized Magic. Perhaps the Celtics would overlook their opponent — a nasty tendency in past seasons.

Nope. Back to the drawing board. Another quick turnaround.

“Got to go through a game like this,” Mitchell said. “Got to get that to understand it. They came out here and did what they were supposed to do. Now we’ve got to find a way to steal Game 2.”

Up next

The Cavs and Celtics will play Game 2 of the Eastern Conference semifinals Thursday night. Tipoff is set for 7 p.m. at TD Garden.