Ireland are on the cusp of the Rugby World Cup quarter-finals after a thrilling 13-8 victory over defending champions South Africa in a riveting Pool B match at the Stade de France on Saturday.

The Irish top the pool and round off their campaign against Scotland in a fortnight while the Springboks, who are second, play Tonga in their final match next weekend.

The win extended Ireland's record winning run to 16 Tests and brought to an end the Springboks' run of six in a row.

The clash of the world's two top teams, who could feasibly meet again in the final on October 28, did not disappoint.

Early Irish pressure was rewarded with a penalty but Sexton was left to rue his decision.

The Irish skipper went for touch rather than take an almost certain three points as the Springboks won the line-out and cleared, putting the pressure on the Irish.

South Africa did not follow suit when the Irish infringed, taking the three points on offer as Manie Libbok slotted the ball over.

The Irish lineout was, to put it mildly, all over the place with hooker Ronan Kelleher's throwing at fault as they lost four successive ones.

It was Kelleher again who spoiled a great opportunity after a superb run by Hugo Keennan had them a metre from the tryline.

Kelleher knocked on and received a consoling pat on the head -- he looked at that point as if he needed something stronger.

- Libbok's wayward kicking -

Kelleher's evening was proving costly to his teammates as another lost lineout handed the Springboks a scrum close to the Ireland line.

The Irish got out of trouble fortuitously. Jesse Kriel's passed to Siya Kolisi but with the line begging it bounced off the captain's head into Caelan Doris's hands.

Bundee Aki, winning his 50th cap, sparked the Irish into their best spell so far of the match.

The barrel-chested centre producing a lung-busting break from deep inside his half into the Springboks 22.

This time eventually the Irish came away with points and the lead -- Sexton again choosing to go for touch than the posts.

James Lowe's long pass found its way to the unmarked Mack Hansen on the right wing and the Australian-born flyer sped over the line  but he almost over-cooked it by touching down perilously close to the deadball line.

The try stood and Sexton added the extras to make the score 7-3 with six minutes to the break.

The lusciously-locked Faf de Klerk took a pot at goal early in the second-half from inside his own half but the ball came off the bar.

Sexton and Aki urged the massed ranks of Irish fans to raise the decibels as the South Africans pressed from inside the Ireland 22.

They obeyed as the Springboks chose to have a scrum when they were awarded a penalty a few metres from the Ireland line.

Bolstered by fresh reinforcements of forwards, the decision paid off as the Springboks spread the ball wide, Libbok finding Kolbe on his own and he went over.

Libbok, though, sent the conversion wide to leave the Boks 8-7 up.

Kolisi was then withdrawn and Kelleher's nightmare also came to an end with Dan Sheehan sent on.

The seesaw continued as Sexton this time went for goal and converted a penalty from in front of the posts to put the Irish 10-8 up.

South African frustration came to the surface when Damian Willemse knocked on the fullback and flung the ball to the ground.

Libbok's kicking at goal had been an issue in the lead-up to the match and it let him down again as he sent a penalty wide of the posts with 16 minutes remaining.

De Klerk tried again from inside his own half but that too went wide.

The 'Boks came surging into Irish territory and when awarded a penalty they went for a scrum, but the Irish held firm and cleared.

Sexton went off to thunderous roars to be replaced by Jack Crowley and the latter slotted over a penalty in front of the posts with under five minutes to go to make it 13-8.

It was unconfined joy from the Irish a few minutes later when they turned over a Springbok scrum and a memorable victory was confirmed.  

pi/gj