Paris Saint-Germain host Marseille in French football's biggest fixture on Sunday, with the capital club on the verge of a full-blown crisis and OM desperate to end the worst run of results in their history.
PSG missed the chance to reclaim top spot in Ligue 1 when they lost 2-1 at Nancy last weekend, their first league defeat under Carlo Ancelotti meaning that they have now won just twice in eight matches in all competitions.
Meanwhile, Marseille have gone a club record 10 matches without winning in all competitions following their exit from the UEFA Champions League to Bayern Munich at the quarter-final stage in midweek.
That run has drained confidence from the ranks of a Marseille squad that previously appeared as dangerous outsiders in the title race, and they should be ideal opponents for a Paris side feeling the heat as they bid to win a first Ligue 1 crown in 18 years.
However, PSG's Milan Bisevac is wary of the old adage that form counts for nothing on occasions such as this. "OM remain a very good side. Even though they are struggling a little, anything can happen in this type of match," insisted the Serbian international defender.
Bisevac emphasised the importance of the occasion and admitted that his team-mates want revenge for a 3-0 humbling at the Stade Velodrome in November.
"We need to win this weekend to launch us back on the winning track for the final seven games of the season and the race for the title," he said. "No-one has forgotten (the game in Marseille). We lost 3-0 and on Sunday we're going to have to make a good start and stay focused on the one and only priority: defeat OM and take the three points."
Reinforced PSG defence
Bisevac will be hoping to keep his place in the heart of the Paris defence at the Parc des Princes but he faces stiff competition, with captain Mamadou Sakho a contender to return after being benched at Nancy, and Diego Lugano and Alex also expected to be fit.
Ancelotti must also decide whether to recall top scorer Nene after the Brazilian apologised for reacting badly to being dropped last weekend.
Fatigue may be an issue for Marseille, with this game coming hot on the heels of their 2-0 defeat in Munich and ahead of a week which will also see them host Montpellier and face Lyon in the League Cup final at the Stade de France.
However, assistant coach Guy Stephan knows motivation will not be a problem for the OM players. "If the players can't motivate themselves for a game like this then they should do a different job," he said.
With so much attention focused on the Clasico, Montpellier have been quietly getting on with the job of preparing for the visit of Sochaux.
Rene Girard's side top the table on goal difference from PSG, and have a game in hand. "It would be a shame to say we would be happy to finish third now," said Montpellier midfielder Geoffrey Dernis.
Having won 10 and drawn one of their last 11 home games, it would take a brave man to bet against them beating Sochaux, even if the strugglers have improved greatly since Eric Hely replaced Mecha Bazdarevic in the dugout.
Having closed to within four points of top spot last weekend, Eden Hazard-inspired Lille are looking for a fourth win on the bounce when they go to relegation-threatened Brest.
Elsewhere, Lyon can ill-afford any more slip-ups if they are to retain any hope of a top-three finish. Remi Garde's side entertain bottom-of-the-table Auxerre.
French Ligue 1 fixtures
Ajaccio v Saint-Etienne
Brest v Lille
Dijon v Nancy
Evian v Rennes
Montpellier v Sochaux
Valenciennes v Toulouse
Lyon v Auxerre
Caen v Bordeaux
Nice v Lorient
Paris Saint-Germain v Marseille