Cristiano Ronaldo provided Portugal with a major confidence boost ahead of the World Cup when he made a successful return from injury in last night's drubbing of the Republic of Ireland.

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.”

“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,” added Irish 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.”

O’Neill was not too concerned at the margin of defeat, insisting that, had his team shut up shop at 3-1, it would not have seemed too bad a result.

He said: “I feel it is not disheartening in the sense that it was 3-1 and if we shut up shop, it is 3-1 and it doesn’t seem so bad.

“I am not too bothered. I have done this before at club level, trying to chase games and stay as positive as possible, and considering the changes that we made and some of our main players not playing, I don’t think this will kill us off.

"It was as tough a game as we expected it to be. But it was also game that I wanted us to participate in because this it is what it is about: playing one of the best teams in the world heading to the World Cup.

“Portugal played well throughout the match and it was a stern test for us.”