Kevin Doyle's 10th international goal set Ireland on the road to a comfortable victory in Andorra as Giovanni Trapattoni's men completed the first half of their European mission.
Doyle's seventh-minute strike gave Ireland an advantage they never threatened to surrender and when defender Ildefons Lima deflected Aiden McGeady's shot into his own net 13 minutes later, the points were effectively safe.
Russia's victory in Slovakia means they will win Group B if they beat the Andorrans at home on Tuesday evening, but a draw with Armenia will be enough to send the Republic into the Euro 2012 play-offs.
The result was never really in doubt as the gulf in footballing ability was obvious, with Kevin Kilbane, Kevin Doyle and Robbie Keane all finding the back of the net for Ireland in their second European qualifier against Andorra in Dublin last night.
But Andorra may have won over a few critics with their combative display, and they even managed to notch a goal of their own through Christian Martinez's thunderbolt.
Giovanni Trapattoni's team never really got out of second gear but they won't mind as they kept up their 100 per cent record in Group B.
Ireland set their stall out to attack at every opportunity, with Keane and Aiden McGeady standing out with their offensive intent.
McGeady's trickery was running rings around the Andorra defence, and it only seemed a matter of time before the minnows' backline would be breached.
And so it proved as in the 14th minute, Liam Lawrence's pinpoint corner-kick was headed home at the near post by a grateful Kilbane, winning his 106th cap for his country.
In fairness to Andorra, they managed to weather the storm after the goal, but Lawrence almost made it 2-0 on the half-hour mark when he chipped the ball over the keeper but just on the wrong side of the net.
The gap between the Andorran midfield and rearguard was widening with every passing minute as the Irish professionals' fitness levels came into play.
But it was something truly special that doubled Ireland's lead, as Doyle turned inside just outside the right-hand side of the box, before powering a left-footed wonder strike into the corner of the goal.
It was a brilliant goal with the Wolves man using very little backlift, as the ball swerved from right to left past unwitting Andorran keeper Josep Gomes.
Andorra's spirit was undeterred by Doyle's magic though and not long after they had a spectacular strike of their own to celebrate.
Defender Martinez, completely out of the blue, hit a right-footed volley as purely as any player could wish to from outside the area that whistled past Shay Given.
Ireland boss Trapattoni's smiles and high-fives with his assistants soon turned into frosty stares of anger, as he berated his players for not closing Martinez down quicker.
The goal seemed to rattle the home side going into half-time and it showed for the first eight minutes or so after the interval until Keane restored the two-goal advantage and normal service resumed.
Trapattoni's men tried a little more passing and a bit more patience and it paid off as the Tottenham striker scored his 44th international goal with a deft chip over the onrushing Gomes.
Ireland were denied a stonewall penalty as Fernando Silva wrestled Doyle to the ground, but bizarrely Cypriot referee Leontios Trattou barely batted an eyelid.
Trapattoni's charges tried to find another goal to add some gloss to the scoreline but it wasn't to be and they seemed quite content to leave field with the three points in the bag.
Ireland skipper Robbie Keane will be fit for Tuesday night's Euro 2012 qualifier against Andorra after he suffered no reaction to his knee injury in last night's 1-0 win over Armenia.
The 30-year-old striker, who has been struggling with the problem, was substituted shortly after Keith Fahey's winning goal at the Yerevan Republican Stadium last night.
However, manager Giovanni Trapattoni revealed today that he took him off simply as a precaution.
He said: 'I gave him a little bit of a rest because he had, not an injury, but some pain and I wanted to be cautious about it.'
Meanwhile, Ipswich defender Darren O'Dea was expected to resume training today after recovering from a sprained knee, while Hull counterpart Paul McShane has rejoined the squad after missing the Armenia game with a hamstring problem.
However, Fulham winger Damien Duff remains sidelined by a calf strain.
