Napoli, chasing their first European title since Diego Maradona's team won the old UEFA Cup in 1989, were drawn against Arsenal in the quarter-finals of the Europa League on Friday.
Rank outsiders Slavia Prague, who ousted Sevilla in thrilling style on Thursday, were rewarded with a tie against Chelsea, the other English Premier League team in the last eight.
Villarreal and Valencia were drawn together in an all-Spanish tie and Benfica will meet Eintracht Frankfurt, who eliminated Inter Milan with a 1-0 win at San Siro.
Arsenal were initially drawn at home in the second leg against Napoli but the order was reversed by UEFA to avoid a clash with Chelsea, who host Slavia in the return of their tie in London.
Arsenal or Napoli will meet Villarreal or Valencia in the semi-finals while Benfica or Eintracht play Slavia or Chelsea.