The article analyzes the Definition of the Supreme Court of the Russian Federation from March 17, 2020, no. 48-KG20-4. The bookmaker tried to collect unjustified enrichment from the participant of a bet on a Boxing match. The prize was given to him by mistake. The courts did not support the plaintiff, deciding that the rules on unjust enrichment do not apply to the claim for the return of an erroneous payment of winnings. According to the courts, in this case, the claim was from a bet, and they are not subject to judicial protection. The authors of the article substantiate the illegality and illegality of such a decision of the Supreme Court of the Russian Federation. Due to the fact that this Definition will be of a pre-trial nature and lower courts will refer to it as a judicial precedent when making a decision on similar cases, the authors believe that the Definition of the Supreme Court of the Russian Federation No. 48-KG20-4 of March 17, 2020 should be revised in order to streamline judicial practice in complex law enforcement.