[JaredL]

If Porto get at least a point and Liverpool and Marseille draw then Marseille go through because they have 4 points against Liverpool.

If Porto lose and Marseille and Liverpool draw then it's a 3-way tie for second between those three. Ignoring Besiktas, the table is:
Team W D L Pts
Liverpool 1-2-1 5
Porto 1-2-1 5
Marseille 1-2-1 5

So it goes to goal difference between those teams.
Liverpool have 5 goals for and 3 against
Porto have 5 for and 7 against
Marseille have 3 for and 2 against

So Liverpool would advance.