Glenn Whelan celebrates his goal at the Estadio Municipal
Giovanni Trapattoni enjoyed his first win as Republic of Ireland boss after a comfortable victory over Portuguese minnows Lagos on Monday.
Glenn Whelan's volley and a clever chip from Darren Potter put the Irish in control before Marco Carmo made it 2-1.
Andy Keogh added the third but the Republic hit the woodwork three times and wasted numerous openings.
"As long as we continue to create chances, we will eventually start to take them," said Trappattoni.
Trapattoni made four changes to the side that started Sunday's 1-1 draw with Portimonese as keeper Joe Murphy, Whelan, Potter and Keogh got the nod.
But where they had laboured at times at the Estadio Municipal in Portimao, the Republic had already gone close twice through Keogh and Paul McShane at the Estadio Municipal when they took a ninth-minute lead.
Skipper for the night Damien Duff pulled a corner to the edge of the box for Whelan to send in a left-foot volley, which defender Uriel could only help into his own net.
Duff forced a 27th-minute save from keeper Toco and Kevin Doyle glanced a free header across the face of goal seconds later, before Potter extended his side's lead on the half-hour with an audacious chip from 25 yards.
Duff clipped the outside of the post with a curling left-foot shot nine minutes before the break, and then chipped wide with just the keeper to beat within seconds of the restart.
Stephen Hunt hit the post as the Republic threatened to cut loose, but Lagos dragged themselves back into it when captain Carmo stabbed home Vitinha's 52nd minute cross from close range.
However, Keogh restored his side's two-goal advantage after Duff had carved his way into the penalty area three minutes later and substitute Daryl Murphy was denied a fourth first by the post and then by defender Diogo on the line with 17 minutes remaining.
"Scoring four, five or six goals tonight was not important; for me, creating chances was the most important thing," added Trappattoni.
Kieran Westwood made a vital late save for the Republic but Trappattoni was forced to defend his decision to draft the Carlisle keeper into his squad after Colin Doyle's withdrawal.
Bohemians keeper Brian Murphy believes Trappottoni should be looking closer to home for players, and he expressed concern about "Joe Soaps" finding their way into the squad.
"I did not know him, but our scouts told me he played in the (Coca-Cola League One play-off) semi-final against Leeds and played two or three important games," said the Italian.
"We are looking at the young players. We have to look at all the possibilities."
The squad returns to Dublin for Saturday's friendly clash with Serbia and their meeting with Colombia at Craven Cottage five days later.
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