Either side of losing 3-0 and 2-0 away and home to Madrid, Roma saw off Victoria Plzen 5-0 and earned back-to-back wins over CSKA Moscow, which would prove to be enough to seal a place in the last 16.
That is despite losing to Plzen in the return fixture, leaving them two points better off than the Czech side and Russian giants CSKA.
Roma were always expected to join Los Blancos in the first knockout round and so it proved, but their record at this stage of the competition is mixed to say the least.
The 1983-84 European Cup runners-up may have reached the semi-finals last season, where they were beaten by Liverpool on aggregate, but they had lost five successive matches in the round of 16 prior to edging out Shakhtar Donetsk in the second leg 12 months ago.
Eusebio Di Francesco's side have won three and lost three of their last-16 matches to date, overcoming Lyon in 2007 and Real in 2008 - their first two appearances at this stage - before suffering defeats to Shakhtar in 2011 and Real in 2016.
Then came the aggregate triumph over Shakhtar last season that would pave the way for a magical run to the final four, which the Giallorossi will be aiming to replicate this time around.
Roma famously beat Barcelona in the quarters, despite trailing 4-1 from the first leg, thanks to a 3-0 triumph on home soil in the return match. The Italian side tend to perform well at the Stadio Olimpico, winning seven in a row there in continental matches prior to Madrid's 2-0 victory in November.
The Giallorossi have now won eight of their last 16 home matches in the Champions League, qualifying rounds included, and Di Eusebio will know the importance of earning a win of some sort in Tuesday's first leg.
After returning to winning ways domestically with a 3-0 victory away to Chievo on Friday, a little over a week on from shipping seven in a humbling Coppa Italia exit at the hands of Fiorentina, Roma will consider themselves favourites to come out on top in this first leg of a close-to-call tie.
Recent form in Champions League: LWWWLL
Recent form (all competitions): WWDLDW
Like Roma, who were assured of a place in the last 16 of the competition with a couple of games to spare, Porto also had some breathing space as they cruised through the group phase with 16 points from a possible 18.
Porto then went on to beat Galatasaray and Lokomotiv Moscow home and away, as well as getting the better of Schalke in the return match at the Estadio do Dragao, to finish 12 points better off than Galatasaray in third.
There is no doubt that the Dragons are deserving of their place in the knockout stage, then, accumulating more points in the group phase than any other side in the competition.
Having gone unbeaten in their six group matches, Porto are now without defeat in European competition since going down 5-0 to Liverpool in the first leg of their last-16 tie last season. Since then, it is five wins and two draws, setting a club record along the way for successive victories by winning the last five.
That heavy home loss to Liverpool will not be forgotten in a hurry, though, and the Primeira Liga outfit will see this as a chance to put things right.
Porto are competing in the Champions League post-Christmas for a third year in a row, but they have not made it to the quarter-finals since 2014-15. The Dragons have won just one of their last five last-16 ties and have just three wins from 10 overall.
By virtue of finishing top of their group, however, Sergio Conceicao's side have been gifted a winnable tie and will consider themselves favourites to make it through.
Porto are unbeaten in their last five matches on their travels in Europe, most recently beating Galatasaray 3-2 in Turkey, and they have won five of their nine two-legged ties against Italian opposition.
Conceicao may have witnessed his side drop four points in their last two league matches, but their form in Europe has been impressive and not many will write off the Blue and Whites' chances of sealing a place in the last eight for the first time in four years.
Recent form in Champions League: DWWWWW
Recent form (all competitions): WWLWDD
Kostas Manolas returned to training at the weekend and is in contention to feature in the first leg, though Di Francesco may give the centre-back a few more days to recover from a niggling injury issue.
Roma will have a fully fit Edin Dzeko in their starting ranks, meanwhile, with the striker scoring in all five of the Giallorossi's knockout matches in last season's competition.
Porto certainly do not lack experience in goal as they can call upon Iker Casillas, who recently racked up his 100th Champions League victory when the Dragons held off Galatasaray in their final group outing.
Roma possible starting lineup:
Mirante; Karsdorp, Marcano, Jesus, Kolarov; Zaniolo, N'zonzi, Cristante; El Shaarawy, Dzeko, Kluivert
Porto possible starting lineup:
Casillas; Militao, Felipe, Pepe, Telles; Pereira, Torres, Herrera; Otavio, Soares, Brahimi
Head To Head
Porto are unbeaten in their four previous competitive meetings with Roma, knocking out the Italian side in the second round of the 1981-82 European Cup and in the 2016-17 Champions League playoffs.
That most recent encounter two seasons ago saw the Dragons run out 3-0 winners at the Stadio Olimpico through goals from Felipe, Miguel Layun and Jesus Corona following a 1-1 draw in the first leg.
The 2016 loss to Porto was only Roma's second in their last 11 matches against Portuguese clubs, winning five and drawing the other four.
We say: Roma 1-1 Porto
Porto will be looking to continue their dominance over Roma when the sides reunite in the Italian capital on Tuesday, having won those previous two European ties. The Portuguese side are unbeaten in their last five Champions League away matches and the Italian hosts have won seven of their last eight continental matches at the Stadio Olimpico, setting up what should be an incredibly tight opening 90 minutes.
body check tags ::