Yohji Yamamoto showed off his martial-arts prowess at the end of the Y-3 show on Sunday. As the designer stood spotlit in the middle of the Park Avenue Armory, a young man approached, and Yamamoto knocked him down with a kung-fu-like move. The victim lay still, and a woman approached, struck a blow, and Yamamoto went down. The audience cheered as he got up, bowed and left the runway. Afterward, the Japanese design legend explained to the Cut that he is a martial-arts specialist, and that the performance was, in fact, real and not staged. “Already my knee hurts,” Yamamoto laughed.