Bayern and Paris need no introduction after meeting in last season's UEFA Champions League final, while Porto and Chelsea also have an idea of what to expect from one another.
See what's coming up in Wednesday's quarter-final first legs.
Wednesday 7 April
Porto vs Chelsea
Bayern vs Paris
Holders Bayern's Paris rematch
Parisian Kingsley Coman scored the only goal as Bayern beat Paris in the 2020 UEFA Champions League final, and has another chance to be the architect of his local team's downfall as the clubs reconvene in Munich.
However, fate may have intervened on Paris's side this time; Bayern talisman Robert Lewandowski has been ruled out of both legs through injury, whereas Mauricio Pochettino should be able to call on Neymar after several weeks struggling with a leg problem. Bayern's Eric Maxim Choupo-Moting – who represented Paris in the 2020 final – said: "I'm looking forward to the game and the reunion. It's an awesome story."
DNA test awaits Porto
Porto shook up this season's competition by eliminating Cristiano Ronaldo-powered Juventus in the last round, their 3-2 extra-time defeat with ten men in Turin – which earned an away goals victory – prompting coach Sérgio Conceição to say: "We never stopped believing – this is the true DNA of FC Porto."
They may need to be just as tigerish against in-form Chelsea, with the suspensions of Mehdi Taremi and Sérgio Oliveira (the Portuguese club's five-goal European top scorer this term) tilting the odds rather more in the Blues' favour. Home advantage cannot help Porto here either, because both legs of the tie are being played in Seville.
Picture credit: UEFA