Joe Schmidt told his Ireland team at half-time yesterday that the 20 minutes after the break would be key.
As it transpired, it was the gripping eight-minute period after the interval that laid that sealed ultimate glory.
First-half tries from Garry Ringrose, CJ Stander and Jacob Stockdale sealed a 24-15 victory at Twickenham yesterday as Ireland added to the previous Grand Slam feats of 1948 and 2009.
A late Jonny May try put somewhat of a better gloss on the scoreline for Eddie Jones’ side as they failed to recover from the 21-5 half-time deficit.
What did Schmidt tell his troops inside the changing room after 40 minutes of absorbing action at Twickenham?
"I said we have to win the next 20 minutes, go out and keep playing, keep attacking," he told the Marian Finucane Show on RTÉ Radio One.
"For eight minutes, we didn’t do much attacking because we were trying to defend our line, but the next 20 minutes we won 3-0.
"It allowed us that breathing space to allow the late game when we were a little bit disorganised with players in different positions."
Those eight minutes were spent primarily under the cosh as England desperately went in search of a try.
Excellent Irish discipline and an England attack not firing on all cylinders meant the line wasn’t breached, and Schmidt has previous when it comes to substantial leads in big matches.
"I’ve been in a similar situation in a Heineken Cup Final [2012, Leinster v Ulster] of being 22-6 up at half-time, we were 21-5 up, and we felt that if they scored early in the second half they could potentially get momentum and put us under pressure and we managed to stave off those many attacks in that eight minutes and get down the other end and add to our score before they got the chance to add to theirs.
"We did feel that England would finish pretty strongly. Towards the end of the match we did start to lose a few players. We ended up with a very, very young backline."
Meanwhile the victorious homecoming has been postponed due to adverse weather conditions.
Schmidt’s all-conquering team were due to arrive at the Aviva Stadium today at 4.30pm to parade their silverware, but the event has also fallen foul of the adverse conditions.