US loses 4-1 to Senegal in Under-17 World Cup opener
Busio scored on a header off a cross from Joe Scally.
Senegal got goals from Souleymane Faye in the third minute of first-half stoppage time, Aliou Balde in the 72nd, Amete Faye in the 76th and Pape Saar in the 88th.
Tayvon Gray's volley off a pass from Gio Reyna was saved off the line by defender Birame Diaw 10 minutes into the second half.
Gray received a red card in the 87th minute when he fouled Souleymane Faye to prevent the forward from breaking in along on goalkeeper Damian Las.