Both the Dragons and the Eagles have started the season in fine style, Porto winning all six of their matches, scoring 15 goals and letting in only two, whilst Benfica have an astonishing 21 goals to their name from their six games (four conceded), of which five have been won and the other drawn.
Porto haven't beaten Benfica in the league since March 2024
Despite being two points behind, the visitors are unbeaten in their last four Primeira Liga matches against Porto, stretching right back to March 2024.
In that run, the hosts of Sunday's epic encounter have managed to score only four goals against As Aguias, but have conceded 10.
With Vangelis Pavlidis (eight goals) and Gianluca Prestianni (five goals) leading the league scoring charts this season too, those 10 goals are likely to be added to at the Estadio do Dragao.
The last league encounter saw four goals shared in a combative 2-2 at the Estadio da Luz. Andreas Schjelderup and Leandro Barreiro grabbed the goals for Benfica, with Victor Froholdt and Oskar Pietuszewski finding the net for Porto.
Incredible unbeaten records
The Dragons do have a magnificent home league record to protect, which dates back to April 2025 and is currently at 23 games unbeaten and counting.
So far in 26/27, they've won all three home games, conceding just once in the process, indicating that Francesco Farioli's side are going to make life extremely difficult for their visitors.
However, Marco Silva's Benfica are also in a very rich vein of form themselves, and they also have an epic unbeaten record to protect, having not lost in 28 away league games, stretching back to January 2025.
Intriguingly, it was Benfica who were the last visiting team to win at Porto in the Liga Portugal, with Pavlidis scoring a hat-trick on that occasion in a stunning 4-1 victory. How the Eagles would like to repeat the trick on Sunday.
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Benfica will arrive full of confidence
The way in which they earned a win against AC Milan at San Siro in midweek showcased to the wider footballing public just what good form Benfica are in at the moment, and far from being cowed by heading to the stadium of their biggest rivals, they will certainly approach the match with confidence.
Silva's job will be to harness that confidence and not allow his side to believe their own hype. He'll want a polished and professional performance as usual, and if he gets just that, Benfica will take some beating.
They remained completely unbeaten home and away under Jose Mourinho last season, of course (W23, D11), though they were still only good enough to finish in third place, behind both Porto and Sporting.
The lack of a league title despite being 'invincible' will surely rankle with the players and staff, and may give Benfica exactly the motivation they need to win just their second title in the past eight seasons.
All-time record in sight
Furthermore, if they are able to avoid defeat on Sunday, they will equal their all-time record of 56 consecutive Portuguese league games without losing.
That record was set between matchday six of the 1976/77 season and matchday one of the 1978/79 campaign. It ended with a 1-0 defeat... to Porto.
The Dragons, for their part, haven't won consecutive league titles since the three between 2010/11 and 2012/13.
Though they've gone on to win the Primeira Liga four times in the 13 seasons since, they've never managed to defend a title, so any advantage handed to Benfica at this stage might already prove fatal to their chances of finally getting over the line in two successive campaigns.
Expect a classic
What's clear is that no quarter is going to be asked or given by either side, and the match could be another classic encounter between two of Portugal's big three.
Froholdt's concussion could see him miss this match for Porto, whilst Zaidu Sanusi and Pietuszewski are also not expected to feature, the latter because of a niggling muscular concern.
The visitors have a largely clean bill of health, though Alexander Bah's fitness remains a question after being out with a shoulder injury.