Joe Schmidt believes the scalp of England will rank as the best in his time in charge of Ireland.
"It'd be the biggest win we've had so far, without a doubt," he said.
The coach takes this view not to undermine how Ireland performed against Australia and South Africa in November, but to rubber-stamp the significance of the Six Nations and the 2015 World Cup next Autumn.
"The position we're in, what we've got to play for, the year that's in it, the players that have come in and out of the squad, there's a number of things," he said.
"It would be great to give that confidence to the players, to know that they're capable of doing it." The respect Schmidt has for Stuart Lancaster's England has been steadfast even before Ireland lost at Twickenham this time last year.
He has called on the 16th man that is the national stadium can be to push his players over the winning line.
"It will be a massive game because we have had unbelievable support in the Aviva," he added. "Against the French, that support reached a new volume in recent times.
"I don't think we've ever quite had it like we had it against New Zealand in November 2013, but I think this Sunday it will get close to that.
"If we can be in the game, at the death, and get our noses in front, I think it would be just reward for the effort the players have made," emphasised Schmidt.
"And just reward for those people who come and support us and provide a degree of inspiration to the players."