Ronaldo looking to overcome Danes
The Real Madrid forward will lead his men out at the Parken Stadion knowing a draw will be enough to take them to Poland and Ukraine for next summer's European Championships.
Paulo Bento's side currently lead Group H on goal difference from the Danes, with tomorrow night's contest effectively a winner-takes-all showdown.
The draw falls on Portugal's side, though, while Norway, three points shy of the duo, could make things even more complex should they inflict a heavy defeat on Cyprus.
But Ronaldo is looking to take the maths out of the equation and do the simplest thing to earn a place in the championships - get a win.
"Portugal are going to Denmark to win the game, that's our thinking," he told Spanish newspaper AS. "We know there are conditions but we want to win the tie for direct entry That is always the mentality of the team and I am sure we will make it a good match."
Ronaldo did not score any of Portugal's five goals as they beat Iceland 5-3 on Friday - his next will put him clear as his country's fourth leading scorer of all-time - proving their attack is working well heading to Denmark.
Their defence is not polished at the moment, though, and Ronaldo believes the absence of club team-mates Pepe and Fabio Coentrao is a contributing factor, as well as the self-imposed exile of Ricardo Carvalho.
"We very much need Pepe," the 26-year-old added. "But those who are here now are the most important. We can talk about Pepe, but Ricardo Carvalho did not come to Portugal."
The first qualifying fixture between the two ended in a 3-1 win for Portugal, but Denmark midfielder Christian Eriksen believes a sound historical record could stand his side in good stead.
They avoided defeat in their three meetings prior to that Lisbon reverse, and Eriksen told uefa.com: "It would be better to avoid the play-offs, but we can only avoid them by getting a win. We've done well against Portugal before, though."
While Norway have a mathematical chance of making it into second spot, manager Egil Olsen has accepted his side will not be boarding a plane next summer.
"It's possible to say I'm disappointed, but I wasn't exactly optimistic beforehand," the former Wimbledon manager told Norwegian newspaper Aftenposten.
For Cyprus, who have two points from a surprise 4-4 draw in Portugal and a 0-0 draw with Iceland, the only target remains a win to overtake the latter and finish second bottom in the group.