Cobus Reinach and Malcolm Marx scored two tries apiece as South Africa beat Argentina 29-27 at Twickenham to win successive Rugby Championship titles for the first time in their history.

The world champions' relentless forward power ultimately proved the difference as they overturned a 10-point deficit after Argentina led 13-3 early in the first half.

South Africa retained the Rugby Championship title on points difference from arch-rivals New Zealand as a thrilling edition of the southern hemisphere tournament ended in dramatic style.

The Pumas were still 13-10 up at half-time thanks to the first of two Bautista Delguy tries and two penalties from Santiago Carreras, with the Springboks' points coming via a Sacha Feinberg-Mngomezulu penalty and a converted try from scrum-half Reinach.

But hooker Marx's try early in the second half saw the Springboks lead for the first time at 15-13 before Reinach's second of the match gave the Springboks breathing space.

And after Marx went over again, South Africa led 29-13 heading into the last quarter.

Delguy's second try, in the 66th minute, gave Argentina renewed hope.

And with three minutes left Carreras' penalty from the half-way line, which would have reduced South Africa's lead to six points, hit the right post -- in what proved to be a crucial miss.

Carreras' superb cross-kick then allowed Argentina replacement Rodrigo Isgro to score a last-minute try.

The full-back's conversion was just too late to turn the tide in the final act of a game, whose climax was in marked contrast to the Springboks' 67-30 thrashing of the Pumas in Durban last weekend.

- 'Tough day' -

"It was a tough day today," South Africa captain Siya Kolisi told Sky Sports. "All credit to the Argentinian team.

"They came hard and we knew they were going to from the beginning. But once again, for us as a team, I'm so proud of our boys."

South Africa dominated the scrum against an Argentina side renowned for its set-piece strength, with Pumas captain and hooker Julian Montoya saying: "You don't need to be an expert to realise the scrum was our biggest weakness today."

South Africa knew a win would guarantee them the title after New Zealand's 28-14 defeat of Australia in Perth earlier in Saturday's final round of the tournament.

But they were a man down inside two minutes when Canan Moodie was yellow-carded for head-on-head contact with Argentina wing Juan Cruz Mallia.

Argentina made their advantage count with a fourth-minute try when a fine handling move ended with Carreras sending in Delguy at the corner.

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South Africa hooker Malcolm Marx scores the Springboks' second try during their Rugby Championship match against Argentina at Twickenham / © AFP

Carreras landed a fine conversion on a windy day and Argentina led 7-0.

But the Springbok pack shoved Argentina back at a scrum, before fly-half Feinberg-Mngomezulu, fresh from a South African record 37 points in the match in Durban, kicked a penalty.

Carreras' close-range penalty nudged Argentina 10-3 ahead, with Moodie spared a second yellow card for a deliberate knock-on as he attempted to intercept.

Full-back Carreras' second penalty gave the Pumas a 10-point lead.

But centre Damian de Allende's burst took South Africa deep into Argentina's 22, the Springboks then declining kickable penalties in search of a try.

Argentina held out stoutly for several phases, but the try the Springboks had been threatening arrived two minutes before half-time when Reinach darted over for a converted score.

Argentina prop Mayco Vivas was yellow-carded early in the second half for a head-high challenge on Eben Etzebeth and from the ensuing penalty, hooker Marx peeled of a driving maul for a try in the corner.

Feinberg-Mngomezulu could not convert but at 15-13 the Springboks led for the first time to the delight of their fans, who made up the bulk of a crowd of over 70,000 in what was technically a 'home' match for Argentina.

Another scrum penalty paved the way for the sniping Reinach to score his second try and, with Feinberg-Mngomezulu converting, the Springboks were two scores ahead at 22-13.

Argentina then stole South Africa's five-metre line-out but Marx pounced on the loose ball and he eventually forced his way over.

But Argentina were not done with Delguy grabbing his second try of the match in the 66th minute after intercepting a looping pass from Cheslin Kolbe, before Isgro crossed to reduce the score.