Rob Howley believes defending champions Wales will require "an extra-special performance" if they want to launch their RBS 6 Nations title defence in winning fashion.
Wales kick off the tournament against Ireland in Cardiff on Saturday week. It is a reverse of last year's opener that Wales won at the Aviva Stadium.
That success proved the springboard for an unbeaten Six Nations season as Wales landed their third Grand Slam in eight seasons.
And interim head coach Howley knows Wales will need to hit the heights again in the quest for a successful start.
"The one thing when we've played Ireland is they have been titanic struggles, fantastic games," he said.
"The players seem to bring the best out of each other. It is a mouth-watering prospect the opening game.
"Thankfully, the last couple of occasions we have come out on the right side of the scoreboard. Other times, we haven't.
"To come away with a win would be extra special, and we will need an extra-special performance against a very good side.
"That first game is a huge one. In terms of favourites and underdogs, having been involved in the Six Nations as a coach and player, each game is in isolation.
"As far as we are concerned we are looking at that first game against Ireland at the Millennium Stadium."