Irish captain Johnny Sexton scored 24 points to make a spectacular injury return as he became Ireland's record World Cup points scorer in a sparkling 82-8 victory over Romania on Saturday.

Sexton scored two of Ireland's 12 tries as the world's top ranked team recovered from the shock of an early Romanian score -- gifted to them by him -- in a match played in sweltering conditions of around 34 degrees celsius (93 degrees fahrenheit).

On his comeback after a near six-month injury absence, Sexton's tally took him to 102 points and surpassed his predecessor as fly-half Ronan O'Gara as Ireland's record World Cup scorer.

The victory margin in Bordeaux was the largest ever for the Irish at the sport's quadrennial showpiece, eclipsing the 64-7 humbling of Namibia in 2003.   

Romania stunned the Irish in the third minute when Tevita Manumua picked off Sexton's grubber and ran past the labouring Irish fly-half before passing inside to Gabriel Rupanu to touch down under the posts.

Rupanu then missed a simple conversion.

The Irish held an urgent huddle and responded in style.

Sexton started the move involving Bundee Aki and Garry Ringrose before Jamison Gibson-Park raced over to touch down.

The Irish stretched their lead in the 13th minute when Hugo Keenan went over under the posts after spinning acrobatically as he was tackled to touch down.

Sexton converted both.

The early Romanian promise faded as Ireland upped a gear and Tadhg Beirne went over in the left hand corner.

Sexton missed the conversion but the Irish had laid the foundations for a comfortable win.

Rupanu slotted over a penalty but the Irish were now in full flow, producing some wonderful fluent passing moves.

Veteran wing Keith Earls popped up on the left after drifting over from his right wing but dropped the ball just short of the line.  

The Romanians' uphill task was amde even tougher just after the half hour mark as Georgian referee Nika Amashukeli sent fullback Marius Simionescu to the sinbin.

Shortly afterwards the impressive Aki fashioned a try for himself.

The imposing New Zealand-born centre ran at the Romanian defence and with one hand-off bulldozed over the line to ensure the Irish had the bonus point secured before half-time.

Sexton, 38, converted from the left touchline and then scored his first try.

He had to have some medical attention on his wrist following a blow from Fonovai Tangimana's knee.

He knocked over another conversion as Ireland reached half-time leading 33-8.

- Record haul -

Sexton was on hand to convert Ireland's first try of the second-half, hooker Rob Herring going over on his own from a tap penalty.

Man of the match Peter O'Mahony was the next to go over -- Sexton converting to pass O'Gara's previous Irish World Cup points record of 93.

Sexton crowned his return as he went over for his second try, converting it to boot.

He departed soon afterwards to ringing applause -- stony-faced he applauded the crowd back.

The Irish did not let up with Joe McCarthy going over whilst O'Mahony, Beirne and Aki scored their second tries of the mismatch.

pi/bc