Chile, Argentina, Nigeria and Mexico went through to the quarter-finals of the Under-20 World Cup with victories on Thursday.
Argentina beat Poland 3-1 in Toronto with two goals from Sergio Aguero setting up a last-eight tie against Mexico on Sunday.
The Poles had taken the lead through Dawid Janczyk in the 33rd minute, but after Angel Di Maria's equaliser, Aguero produced a superb solo strike before wrapping up the win in the 86th minute.
Mexico found it hard going against Congo but won through 3-0. The Central Americans went in front through a penalty from Barcelona's Giovanni Dos Santos on 23 minutes and their last two goals did not come until the final stages in Montreal, Omar Esparza and Pablo Barrera making sure of progress.
Arturo Vidal grabbed Chile's goal in their 1-0 win over Portugal in Edmonton, but he will miss the quarter-final against Nigeria after he was sent off for a second bookable offence in injury time.
Nigeria won their tie against Zambia 2-1 in Ottawa after going in front after just three minutes thanks to an Uwa Echiejile header. Rodgers Kola brought the Zambians level only for Chukwuma Akabueze's powerful drive to win the game.
The quarter-finals will be played on Saturday and Sunday with the other games featuring the United States against Austria and Spain against the Czech Republic.
