A growing literature examines adverse behavior as unintended consequences of incentives. We test Lazear’s hypothesis that states that if rewards were dependent solely on relative performance then an increase in rewards would induce agents to engage in sabotage activity to reduce rivals’ output. We test this hypothesis using the natural experiment of a rule change in Spanish football, the increase in points for winning a league match from two to three. We find, consistent with Lazear’s hypothesis, that teams in a winning position were more likely to commit offences punishable by dismissal of a player after this change.