Movie star Benicio Del Toro and socialite Kimberly Stewart are celebrating after she gave birth to a baby girl.

Stewart, daughter of iconic rocker Rod, gave birth on Sunday at a Los Angeles hospital.

According to Us Weekly, the rock star and his wife, Penny Lancaster, were at his daughter's side as she delivered his grandchild.

The baby was conceived during a short fling between Stewart and Oscar winner Del Toro, but they are no longer an item.