The hosts had to rally strongly in the second half though, as they were 20-15 down at the break and following a South American try shortly after the restart, 10 points behind before their fightback earned them a well-deserved victory to leave the crowd of close to 9,000 go home happy.

Three second half tries by the Junior Boks moved them past their opponents and onto the top of the tournament log after Australia scored a converted try after the buzzer in the first game to draw with New Zealand in the opening game.

South Africa had the better start, with a good try in the first 15 minutes of play. Flyhalves Kyle Smith and Rafael Benedit first exchanged penalty goals for a 3-3 scoreline, before livewire Junior Bok scrumhalf Haashim Pead scored after darting through a gap.

Pumitas fullback Pascal Senillosa cancelled it out when he ran onto his own grubber and with the conversion good, it was clear that the Junior Boks had their work cut out.

SA centre Demitre Erasmus Argentina winger Bautista Lescano then scored tries which were good reward for some industrious play by both backlines, but some ill-discipline by the Junior Boks allowed Benedit to edge his side ahead with a second penalty goal.

Felipe Ledesma edged Argentina further ahead shortly after the break, but slowly and surely the Junior Boks started to put the squeeze onto their opponents, despite some mis-firing lineouts and scrums.

The Junior Boks celebrate Haashim Pead's second try.

First Pead scored his second try before Junior Bok captain Riley Norton went over to edge the home side closer and eventually past their opponents for the first time in the half, handing his side a 29-25 lead after 53 minutes.

The Junior Boks put in one big hit after the other, but it was their broken field running game that was starting to tell and from another good burst, Gino Cupido finished off in the left-hand corner, with the wing’s try extending the lead even further.

SA replacement prop JD Erasmus had the crowd on their feet shortly after following a strong burst, but the try was disallowed as he was deemed to have used his knees to propel himself forward.

A bit later another “try”, this time by replacement loose forward Batho Hlekani, didn’t stand due to a forward pass, but it was clear the Junior Boks had the upper hand with time running out on the clock.

Some good defence held out a desperate Argentina in the final stages, with determined hits keeping the team in blue and white scoreless in the last minutes, despite a strong attacking spell in the red zone of the hosts.

● In the opening match of the tournament, Australia and New Zealand played to an exciting 29-29 draw. Australia, who held the 17-10 lead at the break, scored a last gasp converted try in the 83rd minute of play to draw level on the scoreboard.

Scorers:

Junior Boks 36 (15) – Tries: Haashim Pead (2), Demitre Erasmus, Riley Norton, Gino Cupido. Conversions: Kyle Smith (3). Penalty goal: Smith.

Argentina 25 (20) – Tries: Pascal Senillosa, Bautista Lescano, Felipe Ledesma. Conversions: Rafael Benedit (2). Penalty goals: Benedit (2).