Shamrock Rovers will face Sparta Prague in Tallaght next week in the second qualifying round of the world's premier competition after a game that had it all in the capital.
The Johnny Kenny-inspired Hoops overcame a limited if spirited Vikingur Reykjavik, who had a penalty kick to force extra-time against the ten-man hosts with the game's last kick, only for Nikolaj Hansen to miss after sending Leon Pohls the wrong way.
Kenny blew two huge openings off the bench in the first leg but he brushed any disappointment to one side, converting twice with aplomb within 20 minutes.
However, Hansen's goal with a third of the game to go and Jack Byrne's subsequent red card ensured nails were bitten right until the wire in Tallaght Stadium.
Eight minutes of injury time had been played when Karl Fridleifur Gunnarsson aimed a ball towards the box and it fell for Valdimar Ingimundarson who was fouled by Pico Lopes.
With Tallaght suddenly a hostile place for Hansen, he projected coolness and then some, only for his shot to hit the outside of the post and go wide.
It was quite a night all around, even if Rovers will feel they have so much to improve on. And, while manager Stephen Bradley may rightly have contextualised the pressure the club was under in recent weeks, there is no escaping from how damaging it would have been had they exited the Champions League at their first go two years running.
The Czech champions will be in another league to Vikingur and the Hoops will be no prisoner to illusion; nor will the locals among the 7,632 Tallaght audience.
Even so, victory here ensured a seven-figure bounty and a guarantee of at least two more ties – job done in some respects.
Admittedly, this felt quite different to the road Shamrock Rovers have been on under Bradley, including in Europe.
The bookmakers, remarkably, made Icelandic champions strong favourites against Irish champions in Dublin, and there was no overwhelming sense of confidence among the home fans, even if qualification would mean so much to the mood and the bottom line.
Without labouring comparisons between the countries mere days after an Icelander took the biggest job in Irish football – and Rovers went out to Breiðablik, losing both legs, last year – Irish teams ought to be reasonably confident in games like this.
Rovers have simply not been hitting their usual notes in 2024. That said, they were better mentally for what happened in 2023, and showed the benefit of that experience 12 months on.
The Hoops had ridden their luck a little in Iceland but were also really dangerous on the break in the last half hour after Kenny's introduction and it was no surprise that he started up top here.
Vikingur forced 16 corners a week back and had two here within just over three minutes, but Rovers did the needful defensively.
Kenny's pace had been hugely problematic in Reykjavik and it was again as he opened the scoring on eight minutes. The Icelanders' dubious high line saw Kenny break in behind from Dylan Watts' delivery into space.
Kenny must have visualised chances like this given his memory of seven days ago and one of Rovers' brightest sparks in a disappointing season so far finished brilliantly after helping onto his left foot.
On 16 minutes, more tepid defending from the visitors saw Byrne presented with the ball by Aaron Greene and he found Gary O'Neill with the perfect through-ball.
O'Neill, in a rare one-on-one, was forced into reverse by Karl Fridleifur Gunnarsson and the attack faded into a hopeful Trevor Clarke drive that was deflected out for a corner.
Kenny made it 2-0 on 20 minutes. Again Watts put him into space; the native of Sligo ran at the visitors' backtracking defence; and he slotted home in the manner of a man full of confidence.
It shone a fairly unflattering light on the visitors' rear guard and indeed on goalkeeper Gunnarsson but Rovers cared little.
The second quarter involved very little of note. One can tell that Rovers are still making silly mistakes and need their key players fit again, yet there was no great inkling as yet that Reykjavik might expose them.
Still, Bradley needed to ensure they knew this tie was far from over when they convened for a half-time chat.
Were a reminder needed, Rovers had one just over three minutes into the second half. From around three yards out, Ari Sigurpalsson's only real task was to keep the ball down from a cross down the right, but he got under it and Rovers had massively gotten away with one.
More alarm again on 53 minutes as Valdimar Thor Ingimundarson was allowed to stride without pressure into a dangerous area but he dragged his effort badly wide. Clearly, this game was not over yet.
Pico Lopes had made yet another good clearance moments before Vikingur made it interesting on the hour mark.
Ari Sigurpalsson delivered a vicious right-footed cross onto the head of sub Hansen and, despite a brave effort, Pohls was beaten.
Josh Honohan, now switched left after Neil Farrugia's introduction, pulled wide as Rovers attempted an immediate response. We had a ball game.
Shortly afterwards, Darragh Burns was introduced so, like in the closing quarter last week, Rovers had ample pace with which to attack and Kenny pulled wide with 23 minutes to go after a dangerous break.
Again Byrne hovered on the game's periphery but he only needs a moment and he brilliantly played Burns in, but he might have squared to Kenny and the chance came to nothing.
Byrne's night turned sour – perhaps bitter, depending on what would happen afterwards – as he was sent off for a second yellow for a silly scythe-movement tackle on Ingimundarson with 16 minutes left, though the Dubliner had clearly been fouled in the build-up.
English referee Jarred Gillett also missed a clear foul on Farrugia, the locals incensed; before Rovers had properly cleared, Viktor Oerlygur Andrason had a half-chance but Pohls bundled it away.
Gillett failed to spot an even more obvious infringement on Seán Hoare and assistant manager Glenn Cronin saw yellow for arguing with the fourth official when the notice was put up for the injury time that would befall a ragged Hoops.
Having withstood one aeriel assault after another, Rovers then worried about Jon Gudni Fjoluson's rasper at the edge of the box, but it tailed off wide.
Pohls had one more cross to bare – and smother – before one last bit of drama as Lopes made his final tackle of the night.
The Hoops skipper did not deserve a night to end on a sorry note after he made one clearance after another.
After having had so many decisions go against them inexplicably over the two legs, Rovers deserved a bit of luck.
Shamrock Rovers: Leon Pohls; Sean Hoare, Roberto Lopes, Dan Cleary; Josh Honohan, Gary O'Neill, Dylan Watts, Jack Byrne, Trevor Clarke (Neil Farrugia 62); Aaron Greene (Darragh Burns 65), Johnny Kenny (Lee Grace 80).
Vikingur Reykjavik: Karl Fridleifur Gunnarsson, Oliver Ekroth, Gunnar Vatnhamar, Jon Gudni Fjoluson; Erlingur Agnarsson (Aron Elis Thrandarson 82), Pablo Oshan Punyed Dubon (Viktor Orlygur Andrason 75), Ari Sigurpalsson (Gisli Gottskalk Thordarson 74), Helgi Gudjonsson (Nikolaj Hansen 46), Valdimar Thor Ingimundarson, Danijel Dejan Djuric (Matthias Vilhjalmsson 46).Referee: Jarred Gillett (England).
