Argentine forward Javier Saviola has kept Monaco's European hopes alive with a hotly-disputed goal to clinch a 1-0 victory over injury-hit Liverpool in Champions League Group A.
The principality club shrugged off their poor form in the French league to claim three points on Tuesday and move above Liverpool into second place with one round of matches to play.
Monaco have nine points, one behind group leaders Olympiakos Piraeus who knocked out Deportivo Coruna with a 1-0 victory. Liverpool are third with seven points.
Last season's runners-up did not show much of the class that took them to the final last season as they struggled to break down Liverpool in the Stade Louis-II.
Saviola went closest to breaking the deadlock in the first half when he lashed a shot across the post, and he pounced after 54 minutes to settle the match.
After appearing to control a clearance with his arm, Saviola fired a shot low into the net from inside the penalty area, prompting Liverpool's players to surround the referee.
Liverpool, who are trailing in eighth in the Premier League, started without leading strikers Djibril Cisse and Milan Baros, both injured, and coach Rafael Benitez was forced to field 22-year-old Neil Mellor as a lone striker.
They were further hampered after two minutes when playmaker Luis Garcia was replaced by Josemi after sustaining a hamstring injury while chasing a ball from Steven Gerrard.
After a wobbly start, Monaco steadily built up some pressure, with Saviola trying to take advantage of some sloppy defending by Steve Finnan.
Although they were enjoying most of the possession, Monaco lacked the inspiration to penetrate Liverpool's rearguard, waiting until the 28th minute for their first corner.
Liverpool could have taken the lead from their first real chance after 36 minutes when Igor Biscan's scuffed volley from inside the area went just past Flavio Roma's left post.
After Saviola's goal, coach Didier Deschamps strengthened his midfield by replacing Uruguay forward Ernesto Chevanton with defensive midfielder Diego Perez.
However Liverpool rarely threatened an equaliser until the 86th minute when Sami Hyypia's close-range header was expertly blocked on the line by Roma.
Four-times European champions Liverpool must now beat Olympiakos at Anfield in their final group game to qualify for the knockout phase.