A petite 15-year-old girl fought off her would-be rapist so fiercely that it led to his conviction for the crime seven years later.

The girl, who’d turned 15 just the day before she was brazenly robbed and assaulted in her Harlem apartment building, managed to draw blood from her attacker, which investigators were able to use for a DNA match.

“Although she was only 4 foot 8 inches tall and 80 pounds, she fought like a lion. She hit and scratched the defendant, and they tumbled, fighting, down three flights of fire stairs,” prosecutor Melissa Mourges said.

Curtis Tucker gave worse than he got – he beat the girl so badly that when she pounded on her apartment door for help, her brother didn’t recognize her, Mourges said.

The crime went unsolved for years, until Tucker was arrested for the push-in robbery of a 74-year-old man in the same apartment building. Police took a DNA sample, and within three days, it identified Tucker as the cowardly thug who’d attacked the teen back on March 1, 2004.

Mourges said the girl had been “completely carefree” as she entered the elevator in her building, followed by Tucker.

The elevator stopped at her floor, and “grainy surveillance video shows what happened next,” Mourges said.

“You could see her legs flailing. He then threw her to the floor as the elevator door closed and the elevator rose to the top floor. He dragged her out of the elevator and into the stairwell. The victim handed him all the property she had – a student Metrocard and a single one dollar bill.”

The enraged Tucker “punched her in the face when she wouldn’t stop screaming, and he choked her repeatedly, causing her to lose consciousness,” Mourges said – but the teen kept fighting.

At the bottom of the fire stairs, Tucker “pulled off her pants and tried to rape her,” but the girl “fought past the defendant, running back her apartment,” Mourges said.

“Her face was so bloody and swollen that her brother did not recognize her when he looked out the peephole, and refused to open the door for her,” the prosecutor said.

The girl suffered a broken nose, blackened eyes, cuts and bruises to her whole body, “and permanent disfigurement in the form of a torn lip that did not heal properly and is noticeable to this day,” Mourges said.

In the stairwell, crime scene cops found clots of blood and clumps of hair, as well as the stolen Metrocard, with a bloodstain, and Tucker’s eyeglasses, all of which were used to piece together a DNA profile.

After Tucker was sentenced to five years for the attack on the disabled 74-year-old in the same building, he had to give up a DNA sample, which is when investigators tied him to the 2004 assault.

Mourges told Manhattan Supreme Court Justice Renee White the girl was too traumatized to appear for the sentencing. “[She] never felt safe again in her building, in her elevator, in her home. She was escorted by family every time she left her apartment, for years after this happened. Every time she looks in the mirror she sees a reminder of what this defendant did,” Mourges said.

White agreed it was “a horrendous crime,” and sentenced Tucker, 46, to the 15 years prosecutors had agreed to in a plea bargain. He’l begin serving that sentence when he finishes doing his time for the robbery in 2014.

Manhattan District Attorney Cyrus Vance said the sentence “brings a small measure of justice to a young woman who was introduced to our criminal justice system far too early in life,” but added that her attacker should have been caught years earlier.

Je noted that the ex-con had three misdemeanor conviction in the years since the attempted rape, but the law doesn’t allow for DNA to be collected for misdemeanor convictions.

“I urge our state lawmakers to correct the flaws in the DNA law to help us solve and prevent these calculated and vicious crimes,” Vance said.