The officer, 37-year-old Ernie Walker of the 15th District, was initially released from the hospital on Tuesday but was re-admitted after a CT scan showed more serious head injuries.
Walker was then reported to be admitted into Hahnemann University Hospital's ICU.
He has been on the force for 14 years. Walker is described by officials as 'a good officer.'
It all started around 4:30 a.m. Tuesday when the officer received a call about a domestic dispute at a home located on the 6300 block of Leonard Street.
Philadelphia Police spokesman Lt. Ray Evers said that a woman was trying to leave for work when her ex-boyfriend forced his way into the house. The man had a restraining order against him and police were called.
Police say Walker remained upstairs trying to contain the man while his partner checked on the status of the restraining order.
That's when a struggle ensued, with officers saying the man grabbed Walker and both of them plunged out the second story window.
Authorities think lawn furniture and the officer's protective jacket may have helped break the fall.
The man tried to flee on his broken leg, but Walker's partner took him down.
Walker suffered head, neck, and back injuries.
"You never know what's going to happen on a domestic call and they do get violent at times. This is a perfect example of how dangerous a domestic situation can be," Lt. Evers said.
The suspect, a 27-year-old who has not yet been identified, was taken to an area hospital as well.
Police say the man has an extensive record, with about 14 prior arrests. Police expect to charge him with assault on a police officer, violating a restraining order, and burglary for forcing his way into that home.