Muay Boran counter against straight punch with elbow break
Defensive action
As the opponent throws a forceful straight punch aimed at your face, evade the attack with a quick sidestep. Simultaneously, deflect the punch with your lead arm and catch the attacking arm at the wrist. This is the most difficult part of the whole maneuver. However, with a lot of practice and a good timing you can actually learn to intercept a face punch and grab the attacking arm.
Counterattacks
As you complete the side step and arm grab, quickly follow up with a forceful forearm strike against the opponent’s arm, aiming at dislocating the elbow joint. The second counterattack should follow immediately: keep a firm grip on the trapped arm, turn your hips towards the attacker and throw a straight knee to his midsection. The preferred targets for this knee strike are the solar plexus, liver or floating ribs.
The Art of Counterattack (Sillapha Kan Tob Toh)
Sillapha Kan Tob Toh or the Art of Counter Attack. An efficient counter attack is delivered to an opponent immediately after his strike, usually exploiting a temporary gap in his defense. Hence, the counter attack is not a defensive action but an advanced system of using an opponent’s offence as a means to efficiently execute one’s own attack.
For a step by step guide to Muay Boran’s Art of Counterattack: https://www.muaythai.it/muay-boran-imba-pdf-book/