Antonio Jackson, 23, pleaded guilty to murder in a Darlington courtroom Tuesday morning, according to court officials.
Judge Thomas Russo sentenced him to 30 years in prison.
Darlington County Sheriff's deputies say last November Jackson stabbed Laverne Lyde, 35, at a home on Clearview Drive near Hartsville.
Lyde was pronounced dead at the hospital.
Officers say the two men had been fighting over a woman.
Jackson has to serve at least 85% of his prison sentence before he's eligible for parole.