The hurt question came up with a smiling Northampton coach Jim Mallinder. Was it the hurt of the first match that spurred his team to physically tear down Leinster on their own patch?

“I think it (hurt) brings the best out of people and I think it brought the best out of our team today,” he said.

Dylan Hartley and Ian Madigan were oddly singing off the same hymn sheet, the match reduced to a simple theatre of battle that Northampton won from the moment Santa Claus had absailed from the roof of the east stand and did a lap in his sleigh.

“We got beat up at home last week,” said Hartley. “Gain line, taking the ball into contact we got held up, the infamous choke tackle. We were so far out of the group . . . we said lets go there [Dublin] and let’s focus on the process, which for us is physicality in the tackle.”

Madigan saw the same issues. Leinster struggled to get the platform their backs thrive on. The penalty count against showed Northampton’s big men effectively slowed down the conveyor belt. Leinster couldn’t get width fast enough or space large enough. Northampton’s hurt oozed out and Leinster perished beneath it.

“I don’t think we brought maximum physicality to the breakdown today,” said Madigan. “I think the penalty count at the breakdown would have shown that and the fact we didn’t get quick ruck ball showed we certainly weren’t accurate enough at the ruck.

"Teams know if they can slow our breakdown down and stop our ball-carriers they will be in with a chance of beating us and Northampton showed that tonight. We are aware of that but at the same time we know if we bring our physicality and we are accurate at the breakdown we can beat any team."

The bright lights
Disappointment was everywhere but in Leinster's minds at least, there was simplicity to what went wrong. Perhaps with all the festive spirit, the bright lights of Aviva and nowhere a dissenting voice raised over Leinster's hot favourite tag, focus may have shifted. Matt O'Connor thought no.

“I don’t think it was complacent, we were inaccurate,” said O’Connor. “We didn’t look after the ball as well as we would have liked. We certainly didn’t look after it as well as we did last week. And that let them into the game. They went out in front and to be fair they played the upper hand quite well.

“They kicked into the corners and drove and made it hard for us to get any field position. And on the back of ill-discipline and the penalty count they had opportunities to do that. And all that was all our fault because we didn’t control field position and we probably didn’t put them under enough pressure.”

From Leinster soaring into the new year with a chasm separating them from the rest and one foot into the knockout stages, the pool has narrowed and become more fraught and dependent on the next two games. But the Leinster outhalf can see some light still.

“Yeah we are four points clear of Northampton and five points clear of Castres so we are still in control of the group,” said Madigan.