Guy challenges Taekwondo student to fight - regrets it instantly

When analyzing the use of martial arts on the street, it is useful to understand that it typically falls into several fairly distinct categories:
Self Defense: Use of force to protect against an unprovoked attack that objectively threatens imminent injury.
Mutual Combat: Two people agree to fight, typically with some degree of understanding about rules, either explicit or implied.
Informals: Holding combat sports-type events, at least loosely hewing to rules, without a formal overseeing body. It’s the fight equivalent of playing volleyball on the beach with friends.
Bouncer: Part of the job involves dealing with aggressive behavior or non-compliance with statutory or establishment rules.
Dojo Storm: There are way more of these than one might imagine.

The video below is Mutual Combat. In these cases, there is typically the two participants - or in Russia dozens of them - and in addition, unfortunately, there always seems to be some fool egging the action on, without actually stepping up himself. In this case, he can be heard repeatedly shouting, “It’s going down.” One participant is wearing a shirt, the other is skins.

The two circle, with Skins in a pantomime of combat sports. If you tell someone untrained to put their hands up, they typically bring their hands up to around the chin, and flare elbows out. This protects nothing.

Shirts is protecting himself not with his hands, but with distance management, from a nearly fully bladed (sideways) stance. This is typical of Taekwondo, or Karate Point Fighting. The stance came to martial arts from fencing, and was popularized by Bruce Lee. Based on the technique used to finish the fight, a Turning Side Kick (or in Korean, Momdollyo Yopchagi), it is very likely that Shirts is a Taekwondo adept.

Shirts feints in and out, faking a lead hand strike, all the while getting reads on his opponent’s footwork, reflexes, etc. It is not known whether Shirts saw an opening for the Rear Leg Round Kick (or in Korean, Dollyeo Chagi), or if he was playing a longer game. The kick is thrown and causes no damage, but it set up damage. And setups are everything - executing a martial arts technique without a setup is the polar opposite of fighting, as it is setting yourself up for a counter.

Skins starts to circle towards Shirts’ back, and it is almost over. A prescient voice can be heard saying, “No, lo va a matar” (Spanish for “Oh no, he is going to kill him”). As Skins steps fully towards Shirts’ back, the setup is complete, and the turning kick is thrown, landing perfectly on the liver. There is a slight pause, which is typical of a liver shot landing. And then …

… on a scale from …
6. Bullet Ant Sting
7. Kidney Stones
8. Child Birth
9. Third Degree Burns
10. Dying of Rabies
… being hit in the liver is approximately a 15.

Skins folds, and indicates he no longer wishes to continue. There is no choice involved - Skins is done.

Shirts acknowledges that he has won, via one of the best Taekwondo techniques landed in a Mutual Combat ever caught on video.

LINK

Taekwondo is a Korean martial art that has served as the earliest martial art learned by several successful fighters in the Ultimate Fighting Championship. Including former champions like Bas Rutten, Benson Henderson, and Anthony Pettis.