April 21, 2004 -- Two Manhattan firefighters saved a battered wife - naked and screaming for help on her fire escape as her husband hovered over her - during a brazen midday attack yesterday, authorities said.

John Vanderstar and Chris Fischer, of Ladder 9 in Chinatown, rushed to the rescue after a passerby ran into the firehouse to report what appeared to be a rape.

The two climbed the fire escape and ordered the man to "back off."

The pair helped the bruised woman - whose name is being withheld by The Post - into another apartment. Cops arrived soon after and arrested the husband for sexual abuse.