Ireland remain in pole position to top Pool B after they beat holders South Africa in a low-scoring but riveting World Cup slugfest in Paris.

Cheslin Kolbe hit back for the Boks but after Libbok failed to convert, Johnny Sexton's penalty put Ireland ahead.

In a nail-biting finish, Ireland's defence absorbed pressure before Jack Crowley's penalty sealed an epic win.

At the end of a brutal and relentless Test battle, South Africa pushed for a match-winning try, but after being repelled by a heroic defensive effort from the world's number one side, the Irish contingent in the 78,452 Stade de France crowd greeted a famous win with thunderous acclaim.

It is Ireland's 16th straight Test win and a major boost to their World Cup hopes having fronted up to a ferocious South African side to put themselves on the cusp of another quarter-final place.

Having beaten Scotland and Romania, South Africa remain on course to reach the last eight but this was their first defeat in nine World Cup matches and they must now regroup after being bested by one of their biggest rivals in a titanic heavyweight dust-up.

But the Springboks will rue their missed chances on a night when their unreliable goal-kicking prevented them from turning momentum in their favour.

Ireland edge first half despite early errors

This had been widely touted as the most anticipated match of the pool stage, pitting the world's top two sides in a fascinating clash of styles: the speed and ruthlessness of the Irish attack against a mighty, parsimonious South African defence that shipped just three points in their opening two games.

While Ireland won 19-16 when the sides met in Dublin last year, it is well known that South Africa are a different beast at rugby's global showpiece.

Boks backs coach Mzwandile Stick had said on the eve of the match that "World Cups are a different story", and during a first half in which Ireland made a series of uncharacteristic errors, his words appeared prophetic.

Indeed, while both sides displayed early nerves, it was South Africa who benefited from a creaking Irish line-out, with Libbok's penalty coming at the end of a move sparked by one of several Ronan Kelleher throws that missed its target.

Despite being roared on by raucous Irish support, the Grand Slam winners seemed out of sorts, the Springbok confidence growing with every ferocious hit on a green jersey and Ireland frustration deepening with every failed attempt to break the three-time champions.

While the brute of South Africa's defence clearly unnerved their rivals, Ireland weathered the storm before momentum dramatically swung seven minutes before the interval when a brilliant carry from the in-form Bundee Aki, who won his 50th cap.

Aki, who earlier landed a crucial tackle on Jesse Kriel, showed pace and power to drive his side up the pitch. This time, Ireland stayed patient and moved the ball smartly before a thunderous roar greeted Hansen touching down - although he came close to the deadball line - after Sexton had come within inches of scoring a superb try of his own.

The veteran fly-half nailed the conversion to put Ireland 7-3 up with the returning feelgood factor helped by Garry Ringrose's return after passing a head injury assessment (HIA).

Springboks fail to capitalise

Despite finishing the first half on top, Ireland's line-out issues continued after the restart but they were given a let-off when a Faf de Klerk penalty from halfway came back off the post.

The Springboks piled on the pressure from there and eventually worked the ball wide to Kolbe, who crossed to move the champions 8-7 in front.

But with Libbok having pushed his conversion attempt wide, Ireland edged back ahead through Sexton's penalty.

Chasing the game, South Africa gradually turned to their much talked-about 'Bomb Squad' - the seven forwards named on the bench - and while Ireland's indiscipline offered the Boks a route back into the game, their kicking woes deepened as Libbok and De Klerk failed to land penalties.

Irish nerves were somewhat calmed by Crowley, Sexton's fly-half replacement, kicking them five points clear.

With the clock ticking down Irish fans roared their team towards victory, and while South Africa found time for one last attempt to snatch the win, those in green turned over a maul as the two nations' first World Cup meeting ended with Irish ecstasy.

Having underlined their status as the world's best team and serious contenders for the Webb Ellis Cup, Andy Farrell's side face Scotland in a fortnight while South Africa take on Tonga next week in their final pool match.

Line-ups

South Africa: Willemse; Arendse, Kriel, De Allende, Kolbe; Libbok, De Klerk; Kitshoff, Mbonambi, Malherbe, Etzebeth, Mostert, Kolisi (capt), Du Toit, Wiese.

Replacements: Fourie, Nche, Nyakane, Kleyn, Snyman, Van Staden, Smith, Reinach.

Ireland: Keenan; Hansen, Ringrose, Aki, Lowe; Sexton (capt), Gibson-Park; Porter, Kelleher, Furlong, Ryan, Beirne, O'Mahony, Van der Flier, Doris.

Replacements: Sheehan, Bealham, Kilcoyne, Henderson, Baird, Murray, Crowley, Henshaw.

Referee: Ben O'Keeffe (New Zealand)

Touch judges: Mathieu Raynal (France) & James Doleman (New Zealand)

TMO: Brendon Pickerill (New Zealand)