Portugal took control in the opening 20 minutes, dominating with 68% possession but failing to capitalise beyond a missed chance by Bruno Fernandes, while Poland, despite having less of the ball, produced a number of encouraging attacking moves but lacked quality in the final moment.
While the visitors continued to pose a threat as the half progressed, Portugal maintained their dominance of possession and came closest to scoring when Ronaldo poked a cross just over the bar, but the game remained goalless at half time.
Portugal came out with much more urgency after the break and were finally rewarded just before the hour mark when Rafael Leao drove from his own box into the opposition half, eventually playing the ball to Nuno Mendes out wide, with the defender clipping a cross to the back post for Leao to bury a diving header into the net.
Who else but Ronaldo added Portugal's second just 12 minutes later, stepping up to convert a penalty after Diogo Dalot's strike hit Jakub Kiwior's arm from close range, calmly chipping the resulting spot kick down the middle to double the lead.
Portugal ran riot in the following minutes, adding three more goals between the 80th and 87th, with a sensational long-range effort from Fernandes, a powerful near-post strike from Pedro Neto, and a fabulous overhead kick from Ronaldo, securing the win in style.
The hosts disappointingly lost their clean sheet just a minute after adding their fifth, as Portugal failed to clear their lines and Dominik Marczuk collected the ball just outside the box, clinically tucking his strike into the bottom right corner to score a consolation for Poland and net his first international goal on his debut.
PORTUGAL VS. POLAND HIGHLIGHTS
Rafael Leao goal vs. Poland (59th min, Portugal 1-0 Poland)
Portugal are on their way to the Nations League quarters, Leao with the goal!
The forward collects the ball inside his own box, drives through the centre of the pitch and into the opposition half before sliding it into the path of the overlapping Mendes.
The defender looks up and chips a dinked cross to the back post, where Leao has continued his run and plants a diving header into the net from close range - superb from the AC Milan forward.
Cristiano Ronaldo goal vs. Poland (72nd min, Portugal 2-0 Poland)
That is cheeky from Ronaldo, 2-0 to Portugal and surely game over now!
Portugal are awarded a penalty after a superb bit of play around the box, with Dalot's effort being blocked by Kiwior's arm, albeit from very close range.
Ronaldo does not care though, stepping up to take the penalty and cheekily chipping it down the middle as Marcin Bulka dives away, giving Portugal their second of the night.
Bruno Fernandes goal vs. Poland (80th min, Portugal 3-0 Poland)
That is sensational from Fernandes, 3-0 to Portugal!
Fernandes drives towards the box but has few options to pass to, so he opts to strike from range, and his effort flies towards the top left corner, smashing off the underside of the crossbar and into the net, leaving the keeper with no chance.
Pedro Neto goal vs. Poland (83rd min, Portugal 4-0 Poland)
Portugal running riot now, Neto adds a fourth!
Ronaldo plays a ball back into the path of Neto inside the box, and the winger takes one touch before unleashing a powerful right-footed strike towards the near post, beating Bulka and flying into the back of the net.
Cristiano Ronaldo goal vs. Poland (87th min, Portugal 5-0 Poland)
Ronaldo with the overhead kick to add a fifth for Portugal, spectacular from the striker!
Vitinha receives the ball inside the box, lifts a cross towards the back post, and with the ball just behind him, Ronaldo acrobatically overhead kicks it into the net, showcasing superb skill from Portugal's talisman.
Dominik Marczuk goal vs. Portugal (88th min, Portugal 5-1 Poland)
Poland score, but it is only likely to be a consolation.
Portugal fail to clear their lines with Poland stealing back the ball just outside the box, and Marczuk makes a bit of space for himself before driving a brilliant finish into the bottom right corner, scoring on his international debut.
MAN OF THE MATCH - CRISTIANO RONALDO
The striker showed why he still gets picked for almost every game for Portugal as Ronaldo scored twice to help them to a fantastic 5-1 win on Friday night, including a stunning overhead kick.
Ronaldo cheekily chipped in a penalty for his first and Portugal's second before acrobatically scoring his brace, while also assisting Neto in Portugal's fourth of the night.
The entire front four all also deserve a shoutout, particularly for the second half performance, with Fernandes, Leao and Neto all showing their quality in the huge win for Portugal.
PORTUGAL VS. POLAND MATCH STATS
Possession: Portugal 66%-34% Poland
Shots: Portugal 19-12 Poland
Shots on target: Portugal 6-5 Poland
Corners: Portugal 3-4 Poland
Fouls: Portugal 9-12 Poland
BEST STATS
WHAT NEXT?
The victory for Portugal, alongside Croatia losing to Scotland in the other League A Group 1 fixture, means that they have secured their progression from the group in top spot, leaving them with nothing at stake other than continuing their unbeaten run when they face Croatia on Monday.
As for Poland, Scotland's victory means that they could avoid relegation and move into third place, the relegation playoff spot, if they secure at least a point when they face the Scots on Monday.