Lazio are guaranteed a place in at least the Europa League play-offs as they are top of the table, while Roma boost their chances of getting into the top 24.
The Biancocelesti put in a dominant performance in Amsterdam to flatten Ajax 3-1 with goals from Loum Tchaouna, Fisayo Dele-Bashiru and veteran Pedro.
It puts them on 16 points from six games in the Europa League, joint top with Athletic Club, but ahead on a superior goal difference of +11.
This guarantees them a place in the top 24 places, which is worth a spot in at least the play-offs, although the top eight is what allows teams to go directly into the Round of 16.
Roma beat 10-man SC Braga 3-0 at the Stadio Olimpico to bolster their position to 14th on nine points.
As things stand, it would still be enough to qualify the Giallorossi for a seeded spot in the play-offs draw.
The top eight go directly into the Round of 16, teams from 9-16 are seeded in the play-offs, facing a side from 17-24.
The sides from 25th place onwards are eliminated from Europe altogether when this phase concludes in January.
