The Springbok pack did not yield in defence against the massive Argentina forwards and their strong ball-carriers won enough momentum for them to dominate both territory and possession.
Flyhalf Morne Steyn enjoyed a marvellous return to form as he steered South Africa to victory, his influence ranging from faultless goal-kicking that brought him three conversions and two penalties, to precise field-kicking that set up wing Bryan Habana’s try and slick handling that led to fullback Zane Kirchner’s opening try.
The Springboks also had a first-half try from flank Marcell Coetzee and, given their convincing lead at half-time, they will be disappointed that they did not claim a bonus point from the match for scoring four tries.
Argentina’s points came from two penalties by flyhalf Juan Martin Hernandez, but they could not capitalise on plenty of possession from turnovers, and struggled to escape from their own territory when under pressure in their first match in the tournament that includes the top three countries in the IRB rankings in New Zealand, Australia and South Africa.
Two incisive attacks down the left and right flanks by wings Habana and Lwazi Mvovo set up an early penalty for the Springboks by Steyn, but the home side were rocked at the same time by the loss of their star hooker, Bismarck du Plessis, with a knee injury. But his replacement, 26-year-old Adriaan Strauss, held his own on his 13th appearance at test level.
Argentina then held on to the ball well, but they could not make headway against the steely Springbok defence at close quarters, forcing Hernandez to launch a pinpoint up-and-under. Kirchner initially claimed the ball, but centre Santiago Fernandez ripped it off the fullback, who then played the ball while lying on the ground, gifting Hernandez a penalty to level the scores at 3-3 after 14 minutes.
But the Pumas failed to control the kickoff, giving South Africa a scrum in their 22. The Springboks were awarded a free kick after an early engagement by Argentina and Steyn drifted away from his marker before passing to Kirchner, who was cutting inside and stepped past two tacklers to score.
Steyn’s sweetly-struck conversion made it 10-3 to the hosts and Argentina, who fell foul of referee Steve Walsh’s whistle in the first half due to their ill-discipline, then gifted another three points to the prolific flyhalf after Sharks wing Mvovo was tackled in the air while taking a high ball, leading to a lineout in Pumas territory, at which they were trapped offsides.
Argentina continued to concede penalties and South Africa used rolling mauls to good effect before one of them brought a try as Coetzee broke blind and charged over the line.
Steyn’s convincing form with the boot continued as he kicked the touchline conversion to give the Springboks control with a 20-3 lead.
Hernandez kicked a penalty before the break and closed the gap to 20-6 after Strauss rushed up too enthusiastically and was caught offsides.
But any hopes Argentina had of getting back in the game were dashed when Hernandez (2) and centre Marcelo Bosch missed three penalties between them in the opening six minutes of the second half.
The scare served to reinvigorate the Springboks as they piled on the pressure, pinning the Pumas in their own half.
A knock-on by wing Gonzalo Camacho gave South Africa a scrum in the Argentina 22, which the visitors collapsed. The Springboks set the lineout and a rolling maul, before Steyn launched a crossfield kick to Habana on the right wing, who leapt high to claim the ball and plunge over the tryline.
Steyn again converted from the touchline, but their hopes of claiming a fourth try and the bonus point in the last 23 minutes were dashed by Argentina’s ability to steal turnovers and some unforced errors on their own behalf.
The debutants had left no one in the 39 000-strong crowd in any doubt about their passion, but their lack of attacking weapons meant they never really threatened the Springboks.
South Africa – Tries: Zane Kirchner, Marcell Coetzee, Bryan Habana. Conversions: Morne Steyn (3). Penalties: M. Steyn (2).
Argentina – Penalties: Juan Martin Hernandez (2).