PHILADELPHIA -- Boston Celtics guard Marcus Smart was ejected less than a minute into the third quarter of Wednesday night's game against Philadelphia for a two-handed shove into the back of 76ers star Joel Embiid.

"Obviously, I was frustrated, because it was a cheap shot," Embiid said afterward. "I didn't see it coming. It caught me off guard.

"But, I mean, I really don't want to talk about it. I don't care."

Smart got tangled up with Embiid at the 11:08 mark of the third quarter while trying to steal a pass intended for the All-Star center on the perimeter.

Two seconds later, after Boston inbounded the ball following the stoppage in play, Embiid caught Smart trying to go by him with what appeared to be an elbow into the left rib cage. Smart then fell to the floor, but no call was made.

As Embiid then began to walk away, Smart stood up, took a step and gave Embiid a two-handed shove in his back, with both arms fully extended. That sent Embiid sprawling to the ground in the corner, and he immediately leapt to his feet and tried to rush back at Smart, with officials, coaches, security guards and players from both teams preventing things from escalating further.

After a lengthy review, the officials hit Smart with a flagrant foul 2 -- resulting in an immediate ejection.

"We needed him out there," said Celtics coach Brad Stevens, who added that he was disappointed in Smart. "Don't get it wrong: We love all that Marcus is. And part of Marcus is his fire.

"As you know, a time or two a year it gets the best of him. But this is just a reminder of how important he is. He knows how we all feel and he knows we all love him. That's just part of it. It's part of a long season."

Smart left without speaking to reporters.

As the call was announced, Smart was cheered off the court by the fans in Philadelphia, and he raised his right hand to egg them on as he walked through the tunnel and back to Celtics' locker room.

"Stuff like that, it gets me going, it gets the crowd going," Embiid said. "And everybody knows that I play better when the crowd is involved. So, that energy was definitely good for us."

Embiid, meanwhile, was hit with a technical foul for his role in the play.

Kyrie Irving made the technical free throw for Boston. But Embiid drained both of the free throws that came with Smart's flagrant 2, then made a layup to turn it into a four-point possession. That began an 8-0 Philadelphia run that got the Sixers back into a game they had trailed by double digits for most of the first half.

Philadelphia would go on to win 118-115, giving the Sixers their first win over the Celtics in four tries this season.

"I actually thought we had started to get sort of a little bit of a rhythm and then momentum a little bit towards the end of the second quarter, and felt that too at the beginning of the third," JJ Redick said. "It certainly helped us from a point-differential standpoint, because we were able to get to the free throw line and knock down a couple of free throws."

Embiid led all scorers with 37 points to go along with 22 rebounds -- and a huge block on a drive by Irving in the game's final minute.

"I've been hearing that these guys can guard me better than anyone else, so I had to come out and show that I'm the most unstoppable player in the league," Embiid told ESPN's Cassidy Hubbarth following the victory.