Collin Morikawa of the United States shot a bogey-free 6-under 64 to take a one-stroke lead after the first round of the Zozo Championship, the only PGA Tour event in Japan, on Thursday.
Morikawa, a two-time major champion, had a birdie-birdie start from the 10th hole and finished the day with four more birdies at Narashino Country Club in Inzai, Chiba Prefecture.
Argentina's Emiliano Grillo and Denmark's Nicolai Hojgaard were among five players a shot back.