It was all going so well. At half-time on Saturday, there was an unfamiliar mood of positivity around the Aviva Stadium.
Martin O'Neill's surprising team selection had succeeded in flummoxing Scotland, even if Jon Walters' lead goal came from the only clear-cut scoring opportunity.
He was offside too as he gathered the rebound from Daryl Murphy's header, with the match officials failing to cover themselves in glory throughout this extremely physical contest.
Nicola Rizzoli, the referee in last summer's World Cup final, was praised by Gordon Strachan and criticised by O'Neill, who felt Steven Naismith called the shots.
But Ireland's downfall was self-inflicted, the concession of a goal immediately after the restart draining belief.
The genesis of John O'Shea's own goal was so unremarkable, it's damning. It was the hosts who tipped off after the restart, working the ball into the direction of Seamus Coleman, whose long punt forward started an ugly game of pinball.
Eventually, Murphy was penalised for a foul and as Ireland complained, Scotland took it quickly and ghosted into the final third. Strachan's half-time sub Ikechi Anya drifted from left to right to execute a one-two with Shaun Maloney as Glenn Whelan and James McCarthy stood off.
Seconds later, Shay Given was picking the ball out of the net after Maloney's errant shot ricocheted off O'Shea. "We fell asleep," sighed O'Neill.
The momentum was lost and Ireland didn't have the invention or the ideas to regain it.
Wes Hoolahan offered sporadic bursts of encouragement, especially the through-ball for Murphy that the Ipswich attacker was unable to convert.
Scotland were caught cold in the first half, with an absence of assurance in possession making life difficult for Strachan's charges. They have enjoyed some good press back home but they were made to look like a very ordinary side.
"They were bawling instructions right, left and centre and I thought we were in control," said O'Neill.
The introduction of Anya halted the frequency of Coleman's raids into opposition territory and Ireland suddenly became very predictable.
"It was amazing how it changed when Ikechi went on and took us much further up the pitch," reflected Strachan. "Because we had more of the ball, we could get it out to the wings."
They were aided by Ireland's willingness to cede possession easily. The withdrawal of Hoolahan with 18 minutes remaining made it clear that Plan B involved launching hit-and-hope missiles into the Scottish area and praying for the best.
Robbie Keane was sent in for Hoolahan in order to feed off the scraps but the Scottish rearguard saw it out reasonably comfortably. Their final switch, replacing Naismith with an extra centre-half in Christophe Berra, reflected the reality of the situation.
When Shane Long came in for Murphy, he joined Walters (pictured) and Jeff Hendrick in the box as the impressive Robbie Brady sent in cross after cross.
Keane might have benefited from playing with Hoolahan; the LA Galaxy veteran still has the mental sharpness to make the right run. Instead, there was an inevitability about the final throes of a derby that was low on quality.
"We were getting some pressure on the ball and we had to go a bit longer in those dying moments because our team was getting tired," explained O'Neill. "Robbie Keane is our best goal scorer."
A continual frustration for the Derry man is the lack of goals from midfield. Whelan and McCarthy now have 91 caps between them and a total of two goals. The inclusion of Hendrick in a midfield three helped in the physical contest, yet he was unable to impose himself in opposition territory.
Harry Arter impressed in his cameo against the English and he might well have come into this match if he hadn't picked up an injury during the week. Aiden McGeady's risk-taking was also missed.
"Harry came on for less than half an hour in the game against England and had a shot," said the Irish boss. "That sort of thing is encouraging because if you have a half-decent shot you might as well use it.
"Some midfield players - attacking midfield players - should not be coming off that field without having at least three or four shots in a game."
That conundrum will provide the 63-year-old with further food for thought after another bitterly disappointing conclusion to a big Aviva day.