The United States moved to the brink of advancing from Group F at the Under-20 World Cup after beating Senegal 1-0 on Thursday.
Josh Sargent, who scored twice in the U.S.'s opening draw against Ecuador, netted his third goal of the tournament in only his second appearance at this age level.
The 17-year-old received the ball in the box, spun around a defender and fired the ball into the net for the only goal in the 34th minute.
Sargent, who has been linked with a move to Werder Bremen when he turns 18, nearly found a second after the hour mark, forcing a diving save from Senegal keeper Mouhamed Mbaye.
The result puts the U.S. atop Group F, and the Americans now need just a point against Saudi Arabia on Saturday to be certain of a place in the second round. Even with a loss, the U.S. could also advance as a third-placed team.
Saudi Arabia, meanwhile, kept their hopes alive by beating Ecuador 2-1 in the other game in Group F.
Abdulrahman Al Yami scored in the seventh and 84th minutes, and Ecuador's rally fell short despite Jordy Caicedo's consolation goal.
France eased into the knockout stage after beating Vietnam 4-0 on Thursday.
Jean Augustin scored twice to atone for a fifth-minute penalty miss, while another scorer was Marcus Thuram, the son of 1998 World Cup winner Lilian Thuram.
France top Group E ahead of New Zealand, who beat Honduras 3-1.
Myer Bevan scored twice, including one in the opening minute, to move New Zealand onto four points, while Honduras lost their second-straight game.
