PHILADELPHIA — Jayson Tatum stuck to his routine.

The Celtics star wasn’t on the court moments before Friday night’s Game 3 here at Wells Fargo Arena. Not even Joel Embiid’s MVP ceremony made him stray from his usual regimen, when he goes to the back of the arena after the final pregame buzzer sounds and before the national anthem is played.

“Nothing different today,” Tatum said. “I could hear it. They had it on the TV and I saw it.”

The Celtics knew and expected what was coming Friday night in Philadelphia. The 76ers hadn’t played a home game in almost two weeks, and they were coming back with home-court advantage in a playoff series against a rival. That would typically be enough for their passionate fanbase to be juiced. Add Embiid’s MVP ceremony to the equation, and there was enough energy to blow the roof off.

The cheers were piercing and deafening. The ceremony was emotional.

It didn’t affect the Celtics.

“They’ve been here before,” Celtics coach Joe Mazzulla said.

“We were locked in,” Al Horford added. “We knew what we had to do.”

Tatum emerged from the back, and maybe even more locked in than usual.

“It just really got me ready to play, right?” he said. “You could feel the energy from the crowd and the building. … As a competitor you like being a part of games like that.”

The Celtics were undeterred. They were unfazed. They expected it all. The ceremony, the crowd, the 76ers using that as fuel for a response to their 34-point loss in Game 2. It didn’t matter. The C’s silenced the crowd early, then shut them up for good with dagger after dagger late. They had every answer for the 76ers and their fans en route to a 114-102 victory as they retook control of this second-round series.

“It was just about us doing our thing,” Horford said. “We understood that when the ball went up it was time to go, time to play, and that’s what we did.”

It was Tatum who set the tone, and it made sense. He only played 19 minutes in Game 2 because of foul trouble, and he looked fresh to start Game 3. He scored 10 points within the first four minutes – outsourcing his production in Game 2 – as the Celtics hit their first five shots and took control early. And even when the Sixers punched back and took a lead, the Celtics always had a response ready.

On a night that the Sixers were supposed to play with more energy, it was the Celtics who had the convincing edge in that category. They were making all the hustle plays, several from Marcus Smart, of course. Jaylen Brown led the charge as they were locked in again defensively and frustrated James Harden (3-for-14, 16 points) for a second consecutive game. Embiid scored 30 points, but seemed to fade down the stretch.

“A team that’s more focused and has more attention to detail usually wins in any sport,” Brown said. “So we wanted to make sure we came out and were locked in.”

Brown (27 points) had another big game on both ends as he continued his impressive postseason. He shook off a tough offensive start to lead the Celtics to a halftime lead, then kept the pressure on. The Celtics successfully attacked Embiid early in the third, which included Brown’s three-point play on him. They took multiple shots from the Sixers but took a double-digit lead into the fourth quarter.

The Celtics led by as many as 13 early in the fourth quarter and staved off several Sixers rallies with clutch shots. Grant Williams was inadvertently stepped on by Embiid, bloodied by the stomp, but came right back in. Boston continued to have a response for everything, whenever the Sixers and their crowd threatened to take over.

When De’Anthony Melton’s 3-pointer cut the Celtics’ lead to 97-92, Malcolm Brogdon answered with a triple from the left wing 17 seconds later. When Embiid made it a four-point game with 3:51 left, Brogdon grabbed an offensive rebound and found Horford for his fifth 3-pointer, and then Tatum hit a tough turnaround jumper.

When Harden made a 3 to cut it back to six with 2:05 left, Tatum responded by draining a step-back 3-pointer at the end of the ensuing shot clock. That sealed a big road win.

“We definitely had some timely shots and if those don’t go in, maybe the game is a little closer,” Brown said. “But big players make big shots.”

Several Celtics, including Mazzulla, spoke of the poise they displayed – especially from Tatum – during crunch time, a period that has gotten away from them at times, including this postseason.

“It’s the playoffs,” Mazzulla said. “We’re playing against a great team. And it goes back to just managing your expectations. What’s our expectation? It’s to win the game and to weather storms and to handle adversity. Every possession is a round and an opportunity. Our only expectation is to be winning at the end of the game. It doesn’t matter in between that.”

Friday night – as an emotional ceremony, an electric crowd and a hungry Sixers team challenged those expectations – the Celtics passed an important test. They were undaunted in doing so.

“It’s not difficult really,” Brogdon said. “We’re so locked in right now. We’re really connected, we’re competing at an extremely high level. We’re not really worried about anything else other than what we got in this locker room. We’re not letting anything distract us.”