Police were called to the Pep Bowling Alley on the 1200 block of South Broad Street around 12:30 a.m.
According to police, a group of five males attempted to enter the party and were informed at the door that it was a private event.
Soon after, a fight broke out between someone in the party and one of the males at the door.
At some point during the altercation, two men pulled out hand guns and began shooting into the party.
The 21-year-old victim was shot and fell to the floor. One of the shooters then stood over the victim and shot him again before fleeing the scene.
The victim was taken to Jefferson University Hospital, listed in stable condition.
Minutes later, three suspects were apprehended a block away from the shooting.
The identities of the victim and the suspects have not been released.