Celtic and Chelsea will be hoping to qualify for the knockout stages of the UEFA Champions League on Tuesday, but both are tasked with tough away trips.
After securing a historic win against Barcelona last time out, Celtic know that another victory against Benfica will send them through to the last 16 for the first time since the 2007-08 competition.
Defending champions Chelsea need to avoid defeat against Italian champions Juventus in Turin to ensure that their fate remains in their own hands heading into the final round of fixtures, while a win will also see them qualify.
Manchester United are also in action but with qualification and top spot in Group H already wrapped up, Sir Alex Ferguson is likely to field an under-strength line-up away at Galatasaray.
The biggest story from Tuesday's action may well come at the Estadio da Luz, where Celtic will hope to draw on some inspiration from the 'Lisbon Lions' of 1967 and qualify from Group G.
After the home win against Barcelona, possibly Celtic's greatest European night since the famous victory in Lisbon 45 years ago, Neil Lennon's side need three more points on Tuesday to achieve their goal.
A win will put them out of reach of both Benfica and Spartak Moscow, who face Barcelona in the early kick-off in Russia, while a draw will maintain a gap of three points to the Portuguese side.
A score draw will also mean they own the tie-breaker against Benfica, who are effectively in a must-win situation.
Chelsea's last-gasp winner against Shakhtar Donetsk two weeks ago means they only need to grab a draw against Juventus to stay on track to reach the last 16, but they can book their spot in the knockout stages with a win.
The Blues are currently one point ahead of the Italian giants in Group E and a draw will keep them in second place at least with only a home clash against Danish minnows Nordsjaelland to come.
Shakhtar are away to Nordsjaelland on Tuesday and face Juventus at home on the final matchday, meaning even a Chelsea loss in Turin will seriously hurt their chances but not drop them out of contention completely.
Manchester United, meanwhile, cannot be caught at the top of their group and are likely to give a youthful side some European experience in the cauldron of the Turk Telekom Arena against Galatasaray.
The Istanbul-based side currently occupy the second qualifying spot but both Braga and CFR Cluj, who face each other in Romania on Tuesday, are hot on their heels.
Group F is also in action on Tuesday with Valencia hosting Bayern Munich. A win for the German side will see them qualify as they would be three points ahead with the advantage in the head-to-head tie-breaker. Valencia can also advance with a win.
The other clash in the group sees BATE Borisov take on Lille in an early kick-off in Belarus, with the hosts looking for a victory to boost their hopes of progressing from the group.