Clive Woodward has tagged the RBS 6 Nations "prime championship in world rugby" ahead of England's championship decider with Ireland in Dublin.
Both teams are poised to take the crown at Lansdowne Road, having won four games each.
And it is moments such as this nail-biting climax which make the RBS 6 Nations a world leader, according to Wooward.
He said: "This championship is never easy. All the games are potential banana skins and well done for winning four out of four to Eddie O'Sullivan, the Irish coach.
"To me it proves the 6 Nations is the prime championship in world rugby. It's better than the Tri-Nations because there are more teams, more personalities, more variety and more thrills.
"This year's been no exception. The bottom line is that Ireland have won four out of four. They're on their home ground and they'll be confident."
The England coach has called on his Grand Slam-chasing players to prove they are equally formidable away from fortress Twickenham.
England were denied the Grand Slam in Dublin two seasons ago when they went down 20-14 in a game postponed until the autumn.
But Woodward is adamant this game has just the sort of pressure his side need.
"I'm excited, not nervous," said Woodward. "I'm looking forward to the week.
"There are four games out of the way and now we're looking forward to Sunday.
"I think we've got a good team. We've improved as the tournament's progressed. It's a big year and a big game.
"We said we didn't want to talk about the Grand Slam until we came within one game of it. Now we're totally focused on Sunday's game.
"Our home record is outstanding, with 21 wins from the last 21 games, and we've lost a couple of big games away from home in the past, but that is all history now.
"To me its great we're playing away. For England, in terms of our development, this is an ideal test. We're playing away against another great team."