The Real Madrid forward struck the Seleccao's equaliser before Helder Postiga scored the winner nine minutes into the second half to give his country all three points.
The reportedly unhappy forward’s mood wasn’t helped in the opening ten minutes as Daniel Da Mota gave the home side a surprise lead with a long range thunderbolt.
After passing up several decent opportunities, Ronaldo hauled his country onto level terms, slotting past the impressive Jonathan Joubert after the Luxembourg goalkeeper had threatened to thwart him once more.
And despite withstanding a barrage of Portuguese pressure before the interval, Luxembourg’s parity lasted nine minutes into the second half when Helder Postiga struck what proved to be the winner after a clever aerial ball from Joao Moutinho to get Portugal’s qualifying campaign up and running.
With a fully fit squad to choose from, Luxembourg coach Luca Holtz rang the changes after his side’s 2-1 loss to Georgia in their last outing. In came Daniel Da Mota, Ante Bukvic and Mathias Jaenisch for Eric Hoffmann, Charles Leweck and Rene Peters.
Portugal boss Paulo Bento also shuffled his pack, naming Pepe, Miguel Veloso, Bruno Alves, Joao Perreira and Postiga in a strong starting eleven. Nelson Oliveira, a goal scorer in the side’s 2-0 win over Panama, surprisingly dropped to the bench.
The early exchanges saw a spirited home side match their more illustrious opponents man for man, looking dangerous on the counter-attack as Portugal monopolised possession.
And it was from one such counter attack that Luxembourg took a shock lead. A raking cross field pass found Da Mota down the left channel, the forward cutting inside with one touch before rifling a right-footed pearler past Rui Patricio into the top left-hand corner of the net.
It was a goal of stunning brilliance and one that startled Portugal into life as the Stade Josy Barthel was transformed into a cacophony of noise. Yet for all of the away team’s possession, clear-cut chances were hard to come by.
But when a team has a player like Ronaldo in its ranks, happy or not, clear openings aren’t always a necessity.
The Real Madrid star became the first man to test Joubert, when he blasted in a trademark 25-yard free-kick, only to see his effort well tipped over.
And as the Portuguese pressure mounted, Luxembourg eventually cracked.
Lars Gerson was dispossessed after disastrously attempting to play his way out of trouble on the edge of his own penalty area and Ronaldo was slipped in to coolly pass the ball past Joubert via the post for the equaliser.
The confidence the home team had displayed so admirably in the opening stages was fading rapidly and Ronaldo was inches away from giving Portugal the lead, two minutes later.
More hesitancy in the Luxembourg defence allowed Meireles to loft a stupendous pass over the static back-line, but the Real Madrid forward could only bounce the ball against the post, with Joubert emphatically beaten.
With the home side desperate for the half-time whistle, they had their goalkeeper to thank for keeping them level, Joubert producing a tremendous stop to push Postiga’s top corner bound header wide.
And as the 45 minute mark drew ever closer, the Luxembourg penalty area resembled the Alamo, with wave after wave of Portugal attack descending on their goal.
There was still time for another Postiga header, but the Real Zaragoza forward was denied by the post as Holz’s men survived to hear the half-time whistle with their fragile 1-1 score-line still somehow intact.
The respite did Luxembourg little good with the second half starting out in similar fashion, Ronaldo again thwarted by the opposition custodian when clean through on goal.
Chances were mounting for Portugal as the home side retreated further and further into their own half.
So it came as no surprise when Joao Moutinho’s deliciously lofted pass was beautifully controlled by Postiga with his head; the striker turning and scuffing the ball home under pressure from Schnell to give his country a lead they never relinquished.
After a frenetic start to the second half, the game slowed dramatically with Luxembourg seemingly happy to limit the damage against their now dominant opponents.
Chances continued to come and go for Portugal though, with Nani in particular guilty of fluffing his lines when he fired wastefully over from the edge of the penalty area.
At the other end, Luxembourg striker Joachim provided Portugal with a sharp reminder the game wasn’t over as a contest when his turn and shot brought a sharp reaction stop from Patricio.
But that was as close as the home side could get to an equaliser as Portugal closed out the game in relative comfort, ensuring their first World Cup qualifying match ended in victory.