Italy 0-1 Uruguay
Amajita's Group D opponents, Uruguay got their tournament off to a wining start, after recording a 1-0 win over Italy on Sunday afternoon.
The game's only goal after 76 minutes courtesy of a strike from Rodrigo Amraal.
South Africa will lock horns with Italy on Wednesday, while Uruguay will face Japan.
Zambia 2-1 Portugal
One of Africa's hopefuls, Zambia began their campaign with an impressive 2-1 win over Portugal on Sunday morning.
The Zambians raced into a two-goal lead thanks to second-half strikes from Edward Chilufya and Fashion Sakala.
Helder pulled one back for Portugal through Helder in stoppage time but it proved to be nothing more than a consolation.
Iran 1-0 Costa Rica
Iran got off to a winning start after they recorded a 1-0 win over Costa Rica at the Jeju World Cup Stadium.
The game's only goal arrived in the 81st minute courtesy of a strike from Mohammad Mehdi Mehdikhani.