Nobuhito Sato, seeking his first title of the season, fired a 5-under-par 66 on Thursday to take a one-stroke lead after the first round of the 120 million yen Japan Open.
Sato, the winner of six tour titles in his seven years on the tour, carded six birdies and one bogey over the Tokyo Golf Club's 6,908-yard, par-71 course for the advantage over Katsuyoshi Tomori and Mitsuhiro Tateyama.
Tomori also had six birdies before bogeys on the 15th and 17th holes for a 4-under 67 while winless third-year pro Tateyama ran in three straight birdies from No. 12 for his share of second place.
Tour money rankings leader Toshimitsu Izawa is another stroke back at 68 in a five-way tie for fourth, while Taiwan's Lin Keng-chi and Frankie Minoza of the Philippines lead a group of nine golfers at 2-under 69.