What is the Senshu rule that denied Chetan Bhatt Asian Games bronze?

Indian karateka Chetan Bhatt lost to Chinese Taipei's Meng-yu Chung by Senshu after their men's kumite 84kg bronze medal playoff ended 1-1 at Asian Games 2026. Senshu, a tie-breaking rule, is awarded to the athlete who scores the first point without conceding one beforehand. If a match ends in a draw, the competitor who holds Senshu is declared the winner.