Olympique Marseille, the first French club to beat Liverpool at Anfield, dream of upsetting the five-times European champions once again, this time at home, to make the last 16 of the Champions League.
The two sides clash at the Stade Velodrome on Tuesday with both on seven points from five games in a tight Group A, a point behind leaders Porto and one ahead of bottom-placed Besiktas.
Marseille, who stunned Liverpool 1-0 away in October, will qualify if they repeat that feat before their own fans. They could even advance with a draw, providing Besiktas do not win at Porto.
Liverpool, who warmed up for the game by losing their unbeaten Premier League record with a 3-1 defeat at mid-table Reading, will go through if they win in Marseille or if they draw and Besiktas win at Porto.
"There's a difference in class between the two sides but we'll be at home and we'll make life difficult for them," warned Marseille midfielder and captain Lorik Cana, who scored in a 2-0 win over Monaco on Saturday that lifted his team to 13th in Ligue 1.
The home defeat by Marseille was described by coach Rafael Benitez as his side's worst performance of the season but Liverpool have scored goals for fun in their last two European outings, thrashing Besiktas 8-0 and then beating Porto 4-1.
"If you'd told me five minutes after the final whistle against Marseille at Anfield we'd go into the last game knowing a win would secure our qualification, I'd have bitten your hand off at that offer," said Liverpool captain Steven Gerrard.
"We're a different side and a lot more confident than the one which lost to Marseille at home", he added.
It is a huge week for Liverpool on all fronts.
The Marseille game will determine their European route for the rest of the season while Benitez will also meet the club's American owners, when a certain amount of grovelling might be in order after his recent public criticism.
They then play Manchester United on Sunday, when defeat would leave them nine points behind the champions and with hopes of a first league title since 1990 looking slim.
Marseille coach Eric Gerets said he would probably leave out young France playmaker Samir Nasri, who has not played since sustaining an ankle injury in his side's previous Champions League contest, a 2-1 defeat at Besiktas last month.
"At the moment I would say no," Gerets told reporters on Sunday when asked whether Nasri, without whom Marseille often look ordinary, would play.
"It will be a real final between two sides with everything to lose," Belgian Gerets predicted. "Playing with caution would not help. We need to go for it."
Olympique Marseille: 30-Steve Mandanda; 3-Taye Taiwo, 4-Julien Rodriguez, 32-Gael Givet, 24-Laurent Bonnart; 28-Mathieu Valbuena, 19-Lorik Cana (capt), 7-Benoit Cheyrou, 6-Karim Ziani, 10-Boudewijn Zenden; 11-Mamadou Niang.
Liverpool: 25-Pepe Reina; 17-Alvaro Arbeloa, 23-Jamie Carragher, 4-Sami Hyypia, 6-John-Arne Riise; 20-Javier Mascherano, 8-Steven Gerrard (captain), 19-Ryan Babel, 7-Harry Kewell; 18-Dirk Kuyt, 9-Fernando Torres.
Referee: Terje Hauge (Norway)