A corner retirement[1] [2] [3] or corner stoppage[4] [5] – abbreviated "RTD (Retired)" by BoxRec – are terms used in boxing to describe a fight that ends when, during any rest period between rounds, a boxer refuses to continue or their corner pulls them out, thereby forcing the referee to call an end to the fight. In contrast, a technical knockout (TKO) may only be declared by the referee or ringside doctor, at any stage of the fight including rest periods. In either case, an RTD still counts as a type of knockout, and is displayed as a stoppage result on a boxer's win/loss record.
One of the most notable corner stoppages in boxing occurred during the Muhammad Ali vs. Sonny Liston fight on February 25, 1964,[6] the first of their two fights. After six back-and-forth rounds, Sonny Liston, complaining of a shoulder injury, refused to get up from his stool for the seventh round. As a result, Ali became the world heavyweight champion.