Authorities in Braintree say the man was arrested Thursday afternoon during a traffic stop.
The suspect has been identified as 20-year-old Brandon Jones, of Braintree. Braintree police say he's charged with assault and battery.
Authorities say the victim was stabbed Wednesday night at TD Garden during a fight between fans in a balcony just before the end of the Celtics' 95-92 victory. Police say the victim was taken to a hospital with injuries that weren't considered life-threatening.
Braintree police Lt. Michael Moschella says officers found the suspect after Boston police sent out a description of him.
It's unclear if Jones has a lawyer. His arraignment is scheduled for Friday.