A Bronx man was sentenced to 20 years in prison Tuesday for the two-decades-old killing of his neighbor.

Curtis Batchelor, 44, pleaded guilty to first-degree manslaughter in February as part of a plea deal for the 1999 murder and rape of Elsa Grullon, 56.

“The defendant believed he had gotten away with her killing, but in the end, justice prevailed,” said Bronx District Attorney Darcel Clark.

Authorities connected Batchelor to the gruesome stabbing-death of Grullon after he was convicted of a minor offense in 2016 and his DNA was taken.

The sample matched DNA found in Grullon’s vagina and police arrested Batchelor on charges of second-degree murder, rape, assault and criminal possession of a weapon, officials said.

Batchelor stabbed Grullon more than 20 times as he allegedly raped her inside her fifth-floor apartment at 825 Gerard Ave., according to Bronx prosecutors. He had lived one floor below her.

Grullon’s son-in-law, the superintendent of the building at the time, found her May 27, 1999, bleeding from her head and covered in stab wounds.