This is a tale of Portugal's greatest footballing rivalry. Two teams, two cities, one country and one ultimate goal: to be branded their nation's finest football side. And, where better for both sides to underline their credentials as Portugal's top dog than in 'O Clássico'?
Benfica and Porto are Portuguese football's most decorated sides. They have won more domestic and European trophies than any other club. Sporting CP may make up the country's 'Big Three', but it tends to come down to a story of Benfica vs. Porto year in, year out.
The rivalry may well have been intensified by the fact that, geographically, the two sides are based in the country's two largest cities. Lisbon is Benfica's home, and unsurprisingly Porto reside in, well, Porto.
And make no mistake. Even though Portuguese football has perhaps often been overshadowed by their European counterparts, both 'As Águias' (The Eagles - Benfica), and 'Dragões' (Dragons - Porto) boast an illustrious individual history that has seen them reach the upper echelons of European football throughout the last century.
Fortunately for us, both sides face off at least twice a year now. More often than not, there's a couple more contests chucked in towards the end of the campaign such is the domestic dominance of both clubs. But, before we consider the current state of affairs, let's delve a little deeper into the origins of O Clássico - Portugal's finest footballing matchup.
Aside from As Águias, Benfica have been nicknamed 'Os Encarnados' (The Reds, on account of their home strip), and 'O Glorioso'. And, to be fair, their official club name hasn't changed much since their founding all the way back in 1904. Back then, it was 'Sport Lisboa'. Now, it's S.L. Benfica (Sport Lisboa e Benfica). As their full name hints, the country's capital is Benfica's hometown, which is where their 64,642 capacity Estádio da Luz is based.
What about Futebol Clube do Porto then? Well, they have been around slightly longer than Benfica - 1893 was the year 'Azuis e brancos' (blue and whites) made their bow in Portuguese football. Their hometown is Porto, and their beloved Estádio do Dragão.
The first ever meeting between this pair of Portuguese powerhouses came in a 1912 exhibition match. Benfica started as they meant to go on, smashing Porto 8-2. Dragões would have to wait eight years to gain their first clássico victory.
But, following the 1934 inception of the Primeira Liga, Porto pipped their Portuguese rivals to the first ever edition of the competition. Since then, 'Portistas' (Porto supporters) have seen their side win 76 major trophies, including 28 league titles.
Unfortunately for them though, Benfica are, domestically, Portugal's most decorated club. They've won seven more major trophies than their rivals, winning 37 Primeira Liga titles, as well as edging it on the domestic cup front too.
Throughout the 1950/60s, Benfica, spearheaded by Portuguese legend Eusébio, won eight out of ten possible league titles, as well as two European Cups. When Porto won the title in 1978, it was their first championship in an incredible 19 years. The 1990s saw Porto set a record as they won five consecutive titles. As you can see, this is a battle that has swung both ways.
However, interestingly enough, there have been a total of 243 meeting between the two teams, and Porto come out on top. They've recorded 95 wins over Benfica, who are seven behind with 88 victories in O Clássico.
So, Benfica win in terms of domestic trophies. Porto win in terms of overall derby showdowns. How about in European competitions? Benfica will point to the ten European finals they have reached, which is a domestic record. They won back-to-back European Cups in 1961 and 1962, which is undoubtedly the club's most impressive success in Europe.
Porto, however, have excelled even further on the European stage. They've won seven trophies, including the Champions League in 2004, the Europa League in 2003 and 2011, and the European Cup in 1987. Behind Barcelona and Real Madrid, Porto have been the second-most regular fixture in the Champions League group stage. They are also the only Portuguese side to have completed a continental treble.
So how does it look these days? Benfica won last year's Primeira Liga, and have been champions on six further occasions since the turn of the century. Porto, on the other hand, have won the title on ten occasions in the same period. In the league, there have been 11 victories for Porto since 2009/10, and just five for Benfica.
Overall, the rivalry has developed into an incredibly evenly contested matchup that is often the shining light of the Portuguese footballing season. Both Porto and Benfica have shared the spoils of domestic trophies in recent times, and derby showdowns are always fiercely contested such is the balance of the competition.
Ultimately, both sides are good enough to claim to be their country's finest footballing side. And, more often than not, their success in the various O Clássico contests is crucial in determining either sides end of season successes.