BOSTON -- The Boston Celtics spent the past 48 hours feeling "angry and pissed," according to coach Joe Mazzulla, after the way they dropped Game 1 of the Eastern Conference semifinals to the Philadelphia 76ers at home. So from the opening minutes of Game 2 on Wednesday night, Celtics guard Jaylen Brown was determined to set a different tone for the rest of the team to follow.

Brown knocked down a 3-pointer on Boston's first offensive possession of the game, answering an opening bucket from Tobias Harris, and then proceeded to pick up James Harden from the moment the Sixers inbounded the ball to defend him full court.

It all led to a dominant effort from the Celtics, who responded with 121-87 victory over the Sixers in Game 2. Boston's 34-point win tied for the third-largest margin of victory in a playoff game in franchise history, handed the Sixers their first loss of this postseason and evened the series 1-1. Game 3 is Friday night in Philadelphia.

"We just got to take more pride in ourselves," Brown said after the game. "I felt like we underperformed last game, and we wanted to come out and play to the best of our ability. That's what we did."

Brown led all scorers with a game-high 25 points and helped pick up the slack for Celtics forward Jayson Tatum, who played only 19 minutes and scored seven points after spending most of the game in foul trouble. It's Boston's largest margin of victory in any game in which Tatum was held to fewer than 10 points.

"Our strength is our depth," said Celtics guard Malcolm Brogdon, who tied a franchise playoff record with six 3-pointers off the bench and finished with 23 points. "The way the roster is constructed, we got guys like me, Derrick [White], Grant [Williams] that are playing behind our two superstars and ready to [contribute] when we can."

Meanwhile, the Celtics kept up the intensity on the defensive end all night. They held Harden to 12 points following his 45-point outburst in Game 1 and kept a returning and newly minted NBA MVP Joel Embiid to only 15 points.

"We got to tip our hats to [Brown], he started that whole momentum for us," Celtics guard Marcus Smart said. "We just had to follow his lead. When you've got one of your best players setting the tone like that, it's hard for you not to follow. Our defense has been slipping, and we wanted to come out and get back to what we do best."

Boston's victory Wednesday marks the 15th consecutive time a team that dropped Game 1 of a playoff series at home bounced back to win Game 2.

After being critical of their own defensive effort at the start of the series, the Celtics turned up the intensity on the Sixers on Wednesday night. Harden shot 2-for-14 from the field (0-for-6 on 3s) to finish with the worst field goal percentage following a 45-point game in NBA postseason history.

The Celtics tested Embiid in his first game back from a knee injury, putting him in space and attacking him in the pick-and-roll to see how much running he could handle. Embiid went 4-for-9 from the field, although he did finish with five blocks.

Meanwhile, after attempting a season-low 26 3-pointers in Game 1, the Celtics made 20 of their 51 3-pointers in this game, including a barrage of seven 3-pointers during the third quarter that pushed the game out of reach. Boston outscored the Sixers 35-16 in the third quarter, allowing Tatum and Brown to rest for the final period as the Celtics cruised to a victory.

"You never want to go into a game where you feel like you let one go," Celtics forward Grant Williams said. "We did that too much last year, we've done that too much this year. It definitely gives you a certain edge. But now it's a matter of, can you do the same thing the next game.

"Does that edge stay or does that edge go away because now all of a sudden, you've won one and now you take your foot off the gas. You can't do that. For us, it's a matter of maintaining that same physicality, that same intensity, that same approach going into the game. That'll be vital in this series. We can't be the first ones to break."