BOSTON — The Boston Celtics defeated the Philadelphia 76ers 123-91 in Game 1 of their Eastern Conference quarterfinal series on Sunday. Boston led for the entire game, with its advantage reaching 35 points at one stage.

Jaylen Brown scored 26 points, and Jayson Tatum added 25 points on 9-for-17 shooting with 11 rebounds and seven assists in 32 minutes. Tyrese Maxey led Philadelphia with 21 points on 8-for-21 shooting and eight assists.

The 76ers shot 2-for-16 from three-point range in the first half and finished 4-for-23 from beyond the arc. Boston held a 22-3 advantage in points off turnovers.

"That was Celtics basketball. We've been a hard-playing team all year; that can't change now that the playoffs have started. Our offense can't win us this series." Brown said after the game.

Celtics coach Joe Mazzulla turned his attention to the next matchup. "I thought we got off to a good start in the series, and it really doesn't matter anymore, because in 48 hours we have to do it again. We have to expect a better version of both our opponent and ourselves." Mazzulla said.

Tatum reflected on his path back to the court after recovering from a torn Achilles tendon. He made his season debut on March 6 against the Dallas Mavericks and played 39 minutes in a win over Charlotte and 39 minutes in a loss at New York during the closing weeks of the regular season.

"I understand the magnitude of the injury and the narrative around me coming back, and everything in between. I'm proud of what I've been able to accomplish and return to play, and all those things." Tatum said.

Philadelphia played without Joel Embiid, who underwent an emergency appendectomy in Houston on April 9 and remains out indefinitely. Embiid made his first appearance around the team on Wednesday, sitting on the bench during Philadelphia's 109-97 victory over the Orlando Magic in the 7-8 play-in game. He remained in Philadelphia on Sunday to continue his recovery, and the 76ers aim to extend the series to improve their chances of his return.

The Celtics and 76ers have met six times in the playoffs since Philadelphia defeated Boston in a Game 7 at the old Boston Garden in 1982. Boston won each of those six series.