Almost everything is left to play for on the final night of action in Group E - where even the Champions League holders could crash out.
Genk are merely an active bystander - they will finish bottom of the table whatever happens - but they can certainly help shape the rest of the order.
Napoli will go through if they draw in Naples, or if Red Bull Salzburg fail to beat Liverpool.
Holders Liverpool, meanwhile, need only a draw against Salzburg, or if Genk pull off a surprise against Napoli.
With so much at stake already on matchday 6, here's how to follow all the action on Tuesday night...
TV channel and live stream information
The match will be televised live on BT Sport 1 and can be streamed live online via the BT app and website, with kick-off scheduled for 5.55pm GMT.
You can follow all the action and analysis on Standard Sport's LIVE blog.
Prediction: Napoli 2-0 Genk
The only point Genk have picked up to date in the group came at home to Napoli, but don’t expect Carlo Ancelotti’s side to be as charitable in Naples on Tuesday.
Team news
Napoli: Meret, Di Lorenzo, Koulibaly, Manolas, Rui, Callejon, Allan, Fabian, Zielinski, Mertens, Milik
Subs: Llorente, Lozano, Elmas, Luperto, Insigne, Ospina, Gaetano
Genk: Vandevoordt, Maehle, Dewaest, Lucumi, De Norre, Hrosovsky, Berge, Ito, Paintsil, Onuachu, Samatta
Subs: Wouters, Borges, Odey, Hagi, Bongonda, Coucke, Ndongala
Referee: Cuneyt Cakir
