One person bit a police officer and punched another after the New York Knicks defeated the San Antonio Spurs in Game 2 of the N.B.A. finals. A second person was carrying a loaded gun.

Outside a watch party in Bryant Park on Monday, when the Spurs won Game 3, several men yanked trees from their roots and threw glass at police officers. One Spurs fan was beaten and had his jersey ripped off as he walked back to his hotel. When one New Yorker admonished fans who were shaking a street sign loose.

And on Wednesday, after Game 4, a 17-year-old boy had a seizure and fell into a coma after he was punched and kicked in the head by a group of people on 35th Street, according to police. The assault followed an argument over the game, they said.

These convulsions of violence have generated headlines, but for a city of more than eight million people, such episodes have been relatively sparse. Still, they have revealed a certain frenetic energy beneath the glee and euphoria running through the city this week.

Raucous celebrations are as time-tested a tradition as organized sports themselves. In Philadelphia, the fandom is so passionate that the city has taken to greasing light poles before big games.

But these days in New York, where the Knicks have not had a run at the finals in almost three decades — let alone a title in 53 years — it feels like a pressure valve has been suddenly released, and the long-deferred elation of victory has exploded on streets and sidewalks.