Argentina under 20s made a winning start to their World Cup campaign after a four-goal second half flurry inspired by Ezequiel Barco eventually saw off South Africa in Group F.
A bright start by Fernando Batista’s side in Tychy produced an early breakthrough as Fausto Vera headed in from Cristian Ferreira’s corner after four minutes and it appeared as though La Albiceleste were cruising.
However when Boca Juniors goalkeeper Manuel Roffo failed to claim a South African free kick launched into the penalty area it was left to Keenan Phillips to flick the ball into an empty net and from that point a somewhat rattled Argentina looked vulnerable for the remainder of the first 45 minutes.
After the break La Albiceleste regained some control and eventually retook the lead thanks to a VAR awarded penalty emphatically struck by Ezequiel Barco.
Frustrations perhaps from that decision by the officials led to South Africa goalscorer Phillips seeing red almost immediately after for a foolish kick out at Facundo Medina and Barco punished the Amajita further with a sumptuous curling volley to extend the lead.
Two goals to the good and with the numerical advantage Argentina were now beginning to enjoy themselves and substitute Adolfo Gaich laid on the fourth for Julián Álvarez.
A clumsy challenge by Medina allowed South Africa to pull a goal back from the penalty spot through Lyle Foster but there was still enough time for Gaich to poke in a fifth after Nahuén Pérez had headed down a corner from the right.
Argentina face the far sterner test of Portugal on Tuesday but victory would all but secure a place in the last 16.
Argentina: Manuel Roffo; Facundo Mura, Nahuén Pérez, Facundo Medina, Francisco Ortega; Fausta Vera, Santiago Sosa (Agustín Almendra 81′); Pedro de la Vega (Agustín Urzi 79′), Cristian Ferreira (Adolfo Gaich 58′), Ezequiel Barco; Julián Álvarez