A THIN COVER on the Market-Frankford El's third rail protected a passenger from potentially fatal electrocution after a young man and woman robbed, tased and then pushed him down onto the tracks, SEPTA said yesterday.

SEPTA Transit Police are searching for the couple responsible, who got away with the man's backpack.

The man was sleeping on a mostly deserted car on the westbound side of the Blue Line as it pulled into Millbourne Station about 12:50 a.m. Sunday, according to SEPTA spokesman Andrew Busch.

Surveillance video shows the couple standing over the man as he sleeps. They make a run for it with his backpack once the train car's doors open to what appears to be an empty platform at Millbourne Station.

The man, who was jolted awake by the couple snatching his bag, runs after them and gets in a scuffle with the male assailant. At one point in the video, the victim had the man pinned down on the platform.

"They struggled with each other for a bit," Busch said.

But then, the video shows the woman pulling out what appears to be a Taser, which she jams in the victim's lower back. The two goons push him, limp and unconscious, onto the tracks before fleeing.

The third rail on the El carries about 700 volts, Busch said.

"At some point, he regains consciousness, walks out of the tracks and on to 69th Street Station, where he summoned help," SEPTA Transit Police Capt. Daryl Jones said in a voice-over on the surveillance video, released to media yesterday.

The man was taken to a hospital, where he was treated for non-life-threatening injuries and released, Busch said.

SEPTA police say the robbers boarded the El at the Allegheny Station along Kensington Avenue.

The man is described as white, about 5-10, 150 pounds and 20 to 25 years old, and was seen on station cameras wearing a black knit hat, a white jacket over a gray hooded sweatshirt, green camouflage pants and black Nike sneakers.

The woman is described as white, about 5-6, 120 pounds and 20 to 25 years old, and was seen wearing a gray knit hat, gold hoop earrings, a black jacket with fur trim and black boots. She carried a black purse.

Tipsters can call SEPTA Transit Police at 215-580-8111.

On Twitter: @JBrandt_TU