The Newcastle forward, playing in Japan's final group game, got his name on the scoresheet with an accurate header to draw his side level before half-time.
Following their 2-1 triumph, Japan are unbeaten so far in the tournament with three straight wins and Muto will be hoping to compete in Monday's last 16 clash with Saudi Arabia.
Ki Sung-yueng was not involved in Korea Republic's 2-0 victory over China on Wednesday as he recovers from an injury sustained in their opening game against the Philippines.
Korea Republic, who reached the 2015 final, were another side to register three wins out of three, topping Group C to set up a round of 16 clash with Bahrain.