Pazienza had pleaded guilty to manslaughter in August in a plea deal for eight years in prison.
Todays plea holds Pazienza accountable for her deadly actions.
She will be officially sentenced on September 29.
Lauren Pazienza at sentencing Friday, September 29Getty Images
The two women were not acquainted.
Gustern fell directly on her head, causing a massive hemorrhage to the left side of her brain.
Pazienza then walked away, leaving Gustern on the ground bleeding from her head wound.
Eyewitnesses called EMS and Gustern was rushed to the hospital, where she became unconscious.
She died five days later after she was removed from life support.
Gusterns senseless and shocking death outraged many in the New York theater and cabaret communities.
