Sweet Mask vs. Suppon

You escaped the laboratory and began harming people. The Hero Association asked me to take you in alive... but I'm not that soft. Sweet Mask vs. Suppon was the battle between the A-Class hero Sweet Mask and the awakened caveman Suppon.

Prelude
After escaping from the laboratory he was held in, Suppon goes on a rampage and attacks a nearby town, injuring several civilians. After hearing about this, the Hero Association heads down to the town to deal with the monster.

Battle
While he holds the heads of two unconscious citizens in his hands, Sweet Mask thinks to himself out-loud, saying how Suppon must be the caveman they found frozen and was returned to life, and how he also escaped and began attacking anyone who came close to him. Suppon lets go of the people he has in his hands and growls angrily. Sweet Mask continues by saying he was ordered to bring Suppon in alive, but also says he isn't "that sweet". The mysterious being growls angrily and launches himself at Sweet Mask. However, the hero counters by breaking the monster's leg with a single nonchalant strike, and tells Suppon to pipe down. Sweet Mask then follows up by putting his fingertips on Suppon's cheek, then clenching his hand into a fist that punches Suppon. The force of the punch is strong enough to completely blow apart Suppon's head, killing the monster and making Sweet Mask the victor.

Aftermath
After Sweet Mask kills Suppon, there is purple blood all over his fist that he wipes off. The frightened citizens crowd around Sweet Mask and cheer him on for his victory.

Trivia

 * This battle is practically identical in the anime, manga, and webcomic.