Japan’s Hideki Matsuyama took an early lead in the men’s Olympic golf tournament with a bogey-free opening round, but defending champion Xander Schauffele of the United States was hot on his heels. The first day of competition at Le Golf National, southwest of Paris, was marked by a lively crowd cheering on the home players, Victor Perez and Matthieu Pavon. The weather played a role, with warm sunshine giving way to unsettled conditions that led to two lightning-related delays. Matsuyama’s eight-under-par 63 put him two ahead of Schauffele, who credited a strong finish after a shaky start. Tied for third place at five under were Joaquin Niemann of Chile, Emiliano Grillo of Argentina, and Tom Kim of South Korea.