Gopperth: Munster just tore into us and killed our ball
"It's probably the biggest derby in world rugby," said Leinster's Jimmy Gopperth.
Whether it is or it isn't, Leinster certainly didn't play like it was in the first half at The Aviva Stadium.
They were beaten to the punch in contact and physically bullied by Munster.
"At the start of the game, they just came for us," the out-half stated.
"At every breakdown, they just tore into us and tried to kill our ball. They were very effective at it. They were up pretty hard on defence."
The source of Leinster's ineffectiveness in the first 40-to-50 minutes was beyond Gopperth.
He did not lay the responsibility for Leinster's faults at the feet of his forwards or from Rob Kearney's late withdrawal and the repositioning of Ian Madigan to full-back, Gordon D'Arcy to 12 and Brendan Macken to 13.
"We were definitely up for the game - don't get me wrong there - but, Munster just spoiled our ball really well.
"When we got our ball like that, we just couldn't start well and we couldn't get our flow into the game.
"If you don't get your breakdown right, you can't play rugby. They pushed the letter of the law and got away with it," he said.
"It doesn't matter how disruptive another team is.
"If you go back and do your role properly, get our cleaners quicker, our ball carrier fights harder, it makes the picture a lot clearer than if it's just a pile-up and a scrap".
It was as simple and correct as that. Munster did what Leinster and referee Ian Davies allowed them to do.
There would have been frustration in the Leinster dressing-room at half-time. But their problems needed solutions. Corrections were made,
"We didn't panic. It is one of our best attributes. We knew what we had to. We had to stick to our systems, stick to our roles," he said.
Slowly, Leinster began to find their feet, put Munster under pressure and force a spate of yellow cards.
The reduction in numbers made for more space, two tries, but not even a losing bonus-point.