The shooting happened around 12:30 a.m. inside a house located on the 5000 block of Erringer Place.
According to police, an argument ignited between the girl's new boyfriend and the old boyfriend. At some point, the old boyfriend allegedly pulled out a gun and opened fire, striking the other man in the chest.
The 26-year-old victim then drove himself to 39th District police station on the 2200 block of Hunting Park Avenue in the Tioga-Nicetown section.
Authorities called for paramedics and the victim was then rushed to Temple University Hospital where he is listed in stable condition.
Police say the shooter is known to them and they are searching for him.