Here’s some solid advice: never interfere in a fair fight between two individuals. If you go after the fighter than ends up winning, then you’ll have to pay the price for interfering. A recent fight video between two kids features a sucker kick. Of course, the kicker isn’t even involved in the actual fight, although he’s apparently a friend of one fighter.
The boy he sucker kicks ends up winning the fight and shaking hands with the loser. From there, that interfering kid gets ass beat after attempting to sucker kick during a fair fight. He gets punched in the face repeatedly until he’s dazed. Remember, a fair fight is exactly that, and it’s best to avoid butting in.