Embiid scrambled to foul Tatum as he tried to complete a tomahawk dunk in the fourth quarter of Boston's overtime win on Saturday at Wells Fargo Center. Walking to the free throw line, Tatum could be heard on the broadcast twice telling Embiid, "You got lucky."

During Boston's off-day practice Sunday on the campus of Temple University, Tatum laughed off the trash talk and detailed his relationship with Embiid while recounting the play.

"[Jaylen Brown] got the offensive rebound, and he passed to me cutting through the lane, and I knew Embiid was coming. I just tried to catch him slipping real quick," Tatum said. "I don't really talk trash, and I was just joking. Me and [Embiid] got the same trainer, so we know each other pretty well. We've joked a lot in those games whenever we play each other."

Tatum said Embiid knew he was joking. Tatum missed both free throws that followed, but Boston escaped with a win in overtime to take a 3-0 series lead.

Embiid is renowned for his trash talk, both on the court and via social media, but Tatum is hoping to stash some ammunition for their summer workouts together.

"Hopefully we beat him so I got something to say," he said.

Tatum became the only rookie in Celtics history to score 20 or more points in five straight games, moving past Larry Bird in Boston's record book. As he has for most of the postseason, 20-year-old Tatum shrugged off the suggestion that it's odd for a young player to be so calm on the playoff stage.

"I think, ever since I was young, I just always envisioned myself in these type of moments in the playoffs on the highest level," Tatum said. "It came quicker than I expected, at a young age. But I think it's still basketball at the end of the day. We've all worked our whole lives to get to this point. Now it's just be comfortable out there."

Tatum scored a game-high 24 points on 11-of-17 shooting in Boston's Game 3 triumph. The Celtics swapped spots with the Sixers before last year's draft, and this year's rookie class is under the microscope in this series, even beyond the struggles of Ben Simmons.

As Tatum, the No. 3 pick in the draft, stars for Boston, Markelle Fultz, whom Philadelphia selected No. 1, has yet to see the court and has been a healthy DNP for five straight games. The Sixers sent a future first-round pick to Boston in order to swap spots.

Celtics coach Brad Stevens praised Tatum after Game 3, especially the way he overcame early foul trouble to lead Boston's scoring output. Coming into the postseason, many wondered if Tatum could have the impact he did while starting all 80 regular-season games he played for Boston.

In 10 postseason appearances, Tatum is averaging 18.1 points, 4.7 rebounds, 3 assists and 1.3 steals over 34.8 minutes per game.

"He's got guts," Stevens said of Tatum after Game 3. "He's a competitive guy. Sometimes I think we misconstrue some of these slight guys coming out of college for not being tough, but he's tough. And very competitive."