Before Ireland could take on and beat New Zealand there was another battle to be fought - the mind game.
Failure to win any of the 28 previous Tests had naturally taken a collective psychological toll.
There were a long list of reasons why Ireland were not going to, and could not win in Chicago.
Injuries, withdrawals, a short run-in, an inexperienced bench, an out-half short of match-fitness, an opposition on a record run. Joe Schmidt’s men had no chance.
The perception, from outside the camp at least, was that for these reasons, New Zealand were going to hammer Ireland.
Andrew Trimble battled with and eventually beat the toughest opponent, the one in his head telling him that stopping the juggernaut is impossible.
"You’re wrestling with yourself mentally to go out there with the mindset to try and convince yourself that you’re good enough to do it," the winger told RTÉ Sport after returning to the Kildare training camp.
"People laugh at you if say to them, ‘ah yeah, we’re going to go out and we’re going to beat the All Blacks at the weekend’.
"You try and convince yourself that you’re good enough to do it and be positive and keep attacking."
"That tussle in your mentality [makes it] difficult to keep single-minded and keep positive and keep going at them and keep believing you’re good enough to do it.
"[It’s] not easy in the slightest to get rid of those [factors], to be honest.
"It’s so difficult to go out with a positive mindset and to believe that it’s possible to beat the All Blacks because hardly anybody does it.
"The All Blacks just hammer everybody that they play against."
After defeating doubt, the Ulster back was convinced that the game plan was in place to end an unwanted the 111-year record.
"It’s not something that just happens," said the 32-year-old.
"Obviously, you put a game plan in place and you look after all those little details and then you know if you get all of those things right, which is a big ask, then you might have a chance.
"You try and convince yourself that you’re good enough to do it and be positive and keep attacking.
"And I think we did enough, were positive enough to have enough belief that we could do it in the end, get us over the line."
Next up for Ireland, who are up tot fifth in the world rankings, is a November Series Test against Canada on Saturday, which will be broadcast live on RTÉ2.
However, Schmidt has indicated that he will rest many of the combatants from the Soldier Field encounter.
No matter how they talk it up during the week, the mouth-watering return of Steve Hansen’s side to the Aviva on 19 November will play on the mind of the Ireland camp.
Trimble, who is nursing a minor finger tendon injury, is prepared for a reaction.
"There’s going to be a big backlash," added the 67-cap international.
"We’re going to have to do more hard work because New Zealand are going to produce a bigger performance.
"We can’t just turn up and think we’re going to be the same team again. It would be a mistake to get carried away and think we’re better than we are."
