During the 1984 Amateur World Series, Gourriel hit .309/.356/.636, scored 12 runs and drove in 16 to tie Barry Bonds for the lead. He also led with 7 doubles. Overall, he outproduced Bonds, his counterpart in left field. In the 1985 Intercontinental Cup, he hit .414. He then batted .524 in the 1986 Central American and Caribbean Games.