Marcus Smart's ejection didn't just cost him the chance to help his team stave off a comeback victory against an increasingly bitter rival.

The NBA announced on Thursday that the Boston Celtics guard has been fined $50,000 for shoving Joel Embiid in the back during the Philadelphia 76ers' stirring 118-115 come-from-behind win over the Celtics at Wells Fargo Center on Wednesday.

The incident in question occurred less than a minute into the third quarter. After Embiid sent Smart to the floor with a crushing off-ball screen for J.J. Redick, the notoriously combative Celtics guard rose to his feet and immediately gave the 76ers superstar a two-handed shove from behind that sent him flying.

The pair was subsequently held back by their respective teammates from engaging with another any further. After a video review, officials tagged Smart with a flagrant 2 foul, earning him an automatic ejection.

Boston led Philadelphia 69-58 at the time of Smart's ejection, seemingly en route to a season sweep of the team it beat in five games during last year's Eastern Conference Semifinals.

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But the Sixers, led by Embiid and Jimmy Butler, rallied midway through the fourth quarter, pulling away for good after Butler drained an 18-foot jumper with just over five seconds remaining. Embiid, who's routinely struggled against Al Horford and the Celtics, finished the game with 37 points and 22 rebounds.

“Stuff like that, it gets me going, it gets the crowd going,” Embiid said of his interaction with Smart after the game, per ESPN's Tim Bontemps. “And everybody knows that I play better when the crowd is involved. So, that energy was definitely good for us.”

The Celtics will return to the court on Saturday to take on the Charlotte Hornets.