Had Porto entered this second leg trailing 2-0, it would have taken some effort to turn the tie around. While Roma will bring an advantage into this match, Adrian's 79th-minute strike in Rome has left the tie delicately poised.
Porto were actually unbeaten in their four previous matches against Roma before the first leg, although the last meeting between these two teams in Portugal brought a 1-1 draw in August 2016.
Worryingly, though, Porto are without a win in their last six Champions League knockout matches. Indeed, they were thumped 5-0 by Liverpool at the same stage of the 2017-18 season and have been unable to reach the quarter-finals of this particular competition since the 2014-15 campaign.
Sergio Conceicao's side won all three home games in this season's group stage, though, and impressively collected 16 points from a possible 18 to finish top of Group D. No team performed better in the group stages of the competition, although it would be fair to say that they did have a relatively easy section.
The omens are not fantastic for Porto when considering that they have won just four of the 20 UEFA competition ties where they lost the away first leg. That said, a 2-1 loss in Rome was far from a disastrous result and they will be confident of causing the Italian side a lot of problems on Wednesday night.
The Dragons will enter this match off the back of a damaging league defeat, though, having lost 2-1 at home to Benfica on Saturday. Joao Felix and Rafa Silva scored the goals for the visitors, who now sit two points clear of second-placed Porto at the top of the division.
Facing Benfica in what was a physically-demanding match is not what Porto needed ahead of this fixture, but they have won five of their nine two-legged ties against Italian clubs in European competition.
What's more, Porto have the superior head-to-head record in this particular clash, and Adrian's away goal in the first leg could be crucial as they attempt to turn things around in front of their own supporters.
Recent form: WWWWWL
Recent form (all competitions): DLWWWL
Semi-finalists last season, Roma have won three and lost three of their six previous last-16 ties in the European Cup. They overcame Shakhtar Donetsk at the same stage of the 2017-18 competition before surprisingly going on to reach the last four, where they were ultimately beaten by Liverpool.
The Giallorossi actually lost all three of their away games in last season's knockout phase, however, and were beaten in two of their three away fixtures in the group stages earlier this term. The Italian giants only just squeezed into the round of 16 behind Real Madrid, winning three of their six matches in the section.
It would be fair to say that Roma and Porto would have been pleased to draw each other at this stage of the competition, with both teams managing to avoid a number of European powerhouses.
Roma have actually been victorious in 26 of the 30 UEFA competition ties where they won the home first leg, but they did famously lose 7-1 at Manchester United in the 2006-07 campaign to exit 8-3 on aggregate.
Like Porto, Roma will also enter this match off the back of a damaging league defeat. Heading into the Rome derby with Lazio, Eusebio Di Francesco's had won four straight games in all competitions, but they lost 3-0 to their bitter rivals in Serie A.
As a result, the Yellow and Reds are fifth in Italy's top flight, three points off fourth-placed Inter Milan and four behind third-placed AC Milan with 12 matches of the season left.
Roma have only kept one clean sheet in their last nine away games in all competitions, suggesting that they will not be able to ease their way into the quarter-finals with a goalless draw on Wednesday night.
While it was important to win the first leg, Adrian's late strike means that this tie is delicately poised ahead of what is shaping up to be a fascinating battle at the Estadio do Dragao.
Recent form: WWWLLW
Recent form (all competitions): DWWWWL
Adrian is pushing for a spot in the Porto XI having come off the bench to register in the first leg.
As for Roma, key defender Kostas Manolas has been struggling with both an ankle problem and virus in recent weeks and the Greece international is a huge doubt for the visitors.
Zaniolo limped out of the clash with Lazio at the weekend, meanwhile, but the attacker is expected to be fit as he looks to add to the five goals that he has managed this season.
Cengiz Under, however, has not played since picking up a thigh injury against Torino in January and the in-demand attacker is unlikely to be fit for the Italian giants.
Porto possible starting lineup:
Casillas; Telles, Pepe, Felipe, Militao; Adrian, Danilo, Herrera, Brahimi; Fernando, Tiquinho
Roma possible starting lineup:
Mirante; Florenzi, Fazio, Jesus, Kolarov; Pellegrini, De Rossi, Cristante; El Shaarawy, Dzeko, Zaniolo
Head To Head
Wednesday will bring the sixth meeting between Porto and Roma in European competition.
Porto lead the head-to-head two wins to Roma's one, but the last meeting between the two teams in Portugal ended in a 1-1 draw during the early stages of the 2016-17 competition.
Roma have also previously suffered a 2-0 defeat in Porto, with that result occurring in October 1981.
We say: Porto 1-1 Roma
This is a very, very difficult game to call. It would not be a surprise to see Porto win 2-1 in 90 minutes and force extra time, but we fancy Roma to pick up a draw, allowing them to advance to the quarter-finals.