* Portugal in big win before World Cup
* Ronaldo hits post in first game back
* Almeida scores twice for Portugal (Adds quotes)
By Julian Linden
EAST RUTHERFORD, New Jersey, June 10 (Reuters) - Cristiano Ronaldo provided Portugal with a major confidence boost ahead of the World Cup when he made a successful return from injury in a 5-1 romp against Ireland on Tuesday.
Playing his first match since the Champions League final, Ronaldo's presence helped reignite Portugal's stuttering attack at MetLife Stadium in New Jersey.
Ronaldo was not among the scorers and was substituted after 64 minutes but showed glimpses of his best and came through the friendly unscathed after missing his country's last two warm-up matches because of problems with his left knee and right thigh.
"I think he did well, considering he has not been playing," said Portugal manager Paulo Bento, speaking through a translator.
"Players like Ronaldo are important for every team they play for ... and it's the same for us."
Ronaldo, the World Player of the Year, almost scored in the 18th minute with a dipping free kick that hit the post and again in the 37th minute with a header he directed straight at Irish goalkeeper David Forde.
Hugo Almeida pounced on Forde's rebound to register the second of his two first-half strikes as the Europeans rediscovered their scoring touch after managing just one goal in their two previous friendlies against Mexico and Greece.
Almeida opened the scoring in the third minute when he climbed above the defence and headed a cross from Silvestre Varela into the back of the net.
Portugal scored again in the 20th minute when Fabio Coentrao fired in a low shot from the left that took a wicked deflection off Irish defender Richard Keogh straight over Forde's head.
Trailing 3-0 at halftime, Ireland pulled one back early in the second half when Wesley Hoolahan took a quick free kick and James McClean turned inside and rifled a shot from his left foot into the corner.
"It was a very, very tough game for us, as we expected it would be, with one of the best players in the world starting in the game," said Ireland manager Martin O'Neill.
"He (Ronaldo) of course is absolutely vital to Portugal's hopes of doing well. While they've got a number of really brilliant players, he's obviously one of the two top players in the world."
Portugal dominated the rest of the match, banging in two late goals against an Irish side that failed to qualify for the World Cup in Brazil. Substitute Vierinha scored in the 77th minute when Forde initially saved his header but parried the ball straight back to him.
Then Coentrao finished off the rout when he clinically finished off an inch-perfect pass from Nani, who impressed after replacing Ronaldo for the last 25 minutes and had a late back-heeled goal disallowed for offside.
Midfielder Raul Meireles, who has had a thigh problem, also played 64 minutes while central defender Pepe, who has been struggling with a leg muscle injury, came on for the last 25 minutes in another welcome boost for Portugal who are drawn in the same group as Germany, Ghana and the United States for the World Cup, which starts in Brazil on Thursday.
"We're looking forward to the World Cup," said Bento. "Physically all our players are fit to play so that's good." (Reporting by Julian Linden; editing by Ken Ferris / Ian Ransom)