A “Sucker punch” defined as a blow made without warning, allowing no time for preparation or defense on the part of the recipient. The term is generally reserved for situations where the way in which the blow has been delivered is considered unfair or unethical. In practice this often includes blows delivered from close range or from behind.
Was it? The Mayweather’s alibi on Ruiz 4th round final seconds stoppage “to protect yourself at all times” (even referee Cortez was caught flat footed) but for the unsatisfied millions thought otherwise – for sportsmanship sake could have been (at least) an interesting 12 rounds fist fight if not for his decision to earn mega million purse the easy way. The real loser? All those who shelled dollars expecting a good fight.