Leaders fall and others instantly rise up. Three, possibly four men lost, the Millennium became Seán O'Brien's field, while Rory Best was only phenomenal.

Men who would be captains in any other era and another who will lead them now.

"It was 25 minutes when Johnny came off and Paulie before half-time but it was a calm changing room," said Jamie Heaslip. "Everyone switched into their role and started problem-solving."

This nightmare unfolded before our eyes. Paul O’Connell had his knee heavily strapped before the game. He admitted to being nervous at the captain’s run. Not like O’Connell.

At least Johnny Sexton was his usual ebullient self. He ran from deep, he chipped, he planted two penalties.

Then came sporting tragedy, but only sporting. Freddie Michalak got half a hand to Sexton's garryowen and the ball ricocheted into Scott Spedding's arms. The South African fullback looked almost French, galloping from his 22 and spraying the ball to Brice Dulin. Sexton tracked his error to smash the winger. He went down. Looked like his groin. He got up like lame foal, clipping his hoof up and down. He was fine but Louis Picamoles was out hunting.

Short side

Not a minute after Spedding landed a penalty from inside the French half, after Peter O’Mahony’s high tackle, Sexton clipped his leg up and down following the restart. He drifted into the back field.

Ireland attacked the short side. Sexton sensed Picamoles before feeling the thud and his pass was released just as this insanely powerful number eight landed all his might into the Irish general’s mid-section.

Picamoles broke Sexton before planting him into the Cardiff turf. He vomited on the grass before walking away down the tunnel.

Ian Madigan arrived and instantly darted passes before kicking a high-pressure penalty to steady himself and the magically tuned-in crowd.

Ireland were 9-6 up, 28 minutes gone. What else could possibly go wrong?

O’Connell’s demise was painful to watch. He never stays down but on the stroke of half-time his time in a green jersey, the best of times these past 13 years to witness rugby in Ireland, was no more.

He tried to walk off the field. He could not. He tried to be carried off the field. He could not. They carted O’Connell away.

Iain Henderson arrived and performed like the world-class heir to the throne that he is. An Ulster man in the row feels right. Jeremy Davidson, Paddy Johns, Willie John.

Ireland refused to bend. O'Brien's team now, the pack took over, so clearly playing for their fallen leaders, thumping the French line until the ball went wide to Rob Kearney. He had numbers outside him but he knew Michalak was before him.

He ran over the Toulon playmaker. Try. 14-6. Madigan missed the conversion but Ireland were dominant now.

Michalak struggled to get up and was gone by 54 minutes.

This week people pressed for predictions. The feeling was victory would come at a price. Perhaps four bodies would need sacrificing to keep French goliaths at bay.

Greatest

When Michalak walked, Ireland were without the world’s greatest outhalf and the past two Munster captains as O’Mahony was also driven off the field. Ruined.

There is a citing coming for O’Brien’s early punch of Pascal Papé.

“It was not a closed fist,” Schmidt said, already pleading the flanker’s imminent hearing.

“I think he’s being held and he swung.”

Luke Fitzgerald arrived for Keith Earls after the hour mark. Mathieu Bastareaud followed soon after. No structural damage caused by the wrecking ball centre here.

Earls looked spent, possibly injured, but at least his fumble on 30 minutes when butchering a certain try did not prove detrimental to the result.

The war went on. Heaslip comfortably slipped into the captaincy.

Best led too. The wonderfully bullish O'Brien tackled and pilfered at such rapidity that the statisticians couldn't keep pace. Robbie Henshaw was hard and skilful in equal measure.

A pall spreads over camp Ireland. Only way of lifting it is another famous World Cup victory to follow this famous World Cup victory.

That’s where they have never gone before and the road must now be travelled without their leaders. But new ones have already risen.