You always have to be careful when reading too much into friendly results and even performances to some extent.
When the real business starts many teams can often turn out to be the complete opposite of what they have shown when the pressure is off.
However, the Portuguese fans were right to be a little apprehensive after the recent fixtures with Greece and Mexico.
They managed to keep two clean sheets and stay unbeaten against fellow World Cup finalists which are certainly a positive.
Their lack of a goal threat though was an extreme negative that was beginning to weigh heavy around the player's shoulders.
They did manage one goal, but that was in stoppage time at the end of the Mexico match and was a Bruno Alves header from a free-kick.
With their talisman missing, they looked void of creativity and spark.
The need for Cristiano Ronaldo to return has been growing with every waiting day and he didn't disappoint.
Ronaldo played for over an hour against the Republic of Ireland in his first match since the Champions League final in Lisbon.
Naturally he wasn't at his finest, but considering it was only his second start in nearly six weeks, he was fairly sharp.
A clever flick to Fabio Coentrao led to the second goal, whilst his header was saved by goalkeeper David Forde before Hugo Almeida turned in the rebound.
It was a good workout for the Real Madrid forward as he was able to combine with his colleagues at speed on the attack.
There were no signs of a relapse regarding his injuries and just the very sight of him on the pitch is warming for Seleccao supporters.
"He is one of the top two players in the world. He’s just a brilliant, brilliant player," said Ireland manager Martin O'Neill to the press before the encounter, via The Daily Mail.
Portugal coach Paulo Bento was a relieved man at the final whistle and he will certainly sleep a little easier between now and the opening match with Germany.
"Yes, it was important that he played and we would not hide it," said Bento in the press conference, via Sky Sports.
"A player like Ronaldo is important for any team, and that's the case for us. It's good that he is back. I think he had a good match alongside what we did collectively. Considering he has been without competitive football for a few weeks, I think he did well."
His teammate and former Manchester United companion Nani was equally optimistic: "I think he showed he's good, he's well, and I think he showed he will be 100 per cent."
The team was buoyant as a whole after a decent display and now they can relax a little when they arrive in their Sao Paulo base.
Striker Almeida scored a brace either side of an own goal from Andy Keogh in the first half.
Ireland struck back in the second, but goals from Vieirinha and Coentrao put the game beyond doubt.
Nani seemed rejuvenated and was unlucky not to make the scoresheet himself.
His spectacular disallowed back-heel goal in the final minutes was not only an excellent finish, but showed his desire and link-up play to create the opportunity.
It was only against the Republic of Ireland who has failed to make the competition in Brazil, but it's still scoring five goals in international football.
With Ronaldo moving his way back towards fitness and with confidence high after the rout, Portugal will look forward to their first Group G encounter.