Assistant referee Rosana Paz suffered a "serious burn" after a fan threw boiling water at her during a match in Argentina's sixth tier.
Paz was attacked in the final minutes of a clash between Marquesado and San Martin after her fellow assistant gave a decision against the former, who were the home side and winning 1-0.
Per AS, she said: "I felt them throw hot water onto my back. I called for the referee and asked for cold water to be thrown on the area to calm the burning. They wanted to suspend the game, but we reached an agreement to carry on.