Westbrook appeared to try and climb up the bleaches, pointing at the fan while Wizards staff members did their best to hold him back.
Despite having to be restrained for around a minute, Westbrook ultimately returned to the locker room.
The fan was ejected and an announcement was made over the intercom at the Wells Fargo Centre in that any fan throwing anything near the court will be taken out.
The arena released a statement saying the behaviour was classless, unacceptable, and won't be tolerated.
At the time of Westbrook's departure, the Wizards trailed by 17 - a deficit that grew to 25 once the final buzzer sounded, as the 76ers claimed a 120-95 win to go 2-0 up in the series. Westbrook finished 10 points and 11 assists in 29 minutes of play.
The next two games of the series head to Washington, D.C.
It is not the first time Westbrook's had an altercation with a fan in Philadelphia. During the 2016-17 NBA season, while playing for his former Oklahoma City Thunder, a fan sitting courtside infamously and passionately pulled the finger on both hands directed at Westbrook, who stood there in bewilderment.
