Robbie Keane and Shane Long both struck two goals as the Republic of Ireland thumped Denmark in Aarhus.
Robbie Keane celebrates his opening goal in Aarhus
Nicklas Bendtner hit the Republic woodwork early on but Keane's clever finish on 29 minutes turned the game.
On 40 minutes, keeper Jesper Christiansen's punch rebounded off Keane's back and into the net.
Substitute Long pounced for the third on 54 minutes after debutant Darron Gibson's shot had been parried and the Reading striker hit the fourth on 66.
Steve Staunton caused something of a surprise by leaving Kevin Kilbane on the bench with Darren Potter, Stephen Hunt and fit-again Andy Reid all earning starts in midfield.
Republic goalkeeper Wayne Henderson gave his defence a few jitters by dropping an early corner before the ball was cleared but it was a largely lacklustre opening in Aarhus.
However, the Danes picked up the pace considerably in the 13th minute when Dennis Rommedahl breezed past Steve Finnan and floated over a superb cross which was nodded against the crossbar by Bendtner.
It was a lucky escape for the Irish and they had another moment of concern a minute later when Henderson did well to block a close-range Jon Dahl Tomasson shot after good work by Bendtner.
The Danes continued to look the livelier and Jesper Gronkjaer volleyed over from inside the box in the 25th minute after a deep Bendtner cross.
However against the run of play, the Republic took the lead on 29 minutes with Keane producing a delightful lofted finish over Jesper Christiansen after he had been played in by a defence-splitting Andy Reid pass.
Darron Gibson (right) earned his first Republic senior cap
It was the Republic's record markman's 30th international goal.
There was an element of good fortune about Keane's second goal in the 40th minute although the Tottenham striker was rewarded for his bravery.
Danish goalkeeper Christiansen attempted to punch away McGeady's dangerous cross but the ball rebounded off Keane's back and into the net.
Gibson's introduction was one of three Republic changes at the interval with Shane Long and Andy Keogh also coming on.
Manchester United youngster Gibson is at the centre of a dispute between the Republic and Northern Ireland over his eligibility.
Nigel Worthington has been making attempts to persuade the Derry-born player to switch his allegiance back to Northern Ireland and Staunton will hope that his awarding Gibson a first senior cap ends the controversy.
Gibson made an immediate impact by playing a major part in the Republic's third goal on 54 minutes with Christiansen unable to hold the substitute's long-range shot and Long reacting to fire home the rebound from 12 yards.
Denmark's embarrassment was compounded when Long had acres of space to stroke in the fourth goal on 66 minutes with the home defenders nowhere to be seen.
With the Republic continuing to make substitutions, the Danes had chances in the final quarter with Peter Lovenkrands and Rommedahl guilty of bad misses and Bendtner heading against the Republic woodwork for the second time.
The 4-0 margin flattered the Republic but it was nonetheless a hugely positive evening for Steve Staunton and his squad ahead of next month's Euro 2008 qualifiers against the Czech Republic and Slovakia.
Denmark: Christiansen, Bogelund, Gravgaard, Agger, Niclas Jensen, Wurtz, Rommedahl, Daniel Jensen, Gronkjaer, Bendtner, Tomasson. Subs: Kvist, Kristiansen, Laursen, Kahlenberg, Andersen, Thygesen, Kristensen, Lovenkrands, Nordstrand.
Rep of Ireland: Henderson, Carr, O'Shea, Dunne, Finnan, Reid, McGeady, Potter, Hunt, Kevin Doyle, Keane. Subs: Keogh, O'Brien, Long, Colin Doyle, Kilbane, Murphy, Gibson, Kelly, Colgan.
Referee: Thomas Einwaller (Austria)