Igor Tudor's side defeated Nantes 2-0 on Wednesday night, while Les Aiglons also posted a win and clean sheet of their own, getting the better of Lens 1-0.
Match preview
Thanks to Nice getting the job done against Lens, Marseille were presented with a golden opportunity to leapfrog Les Sang et Or into second place in the Ligue 1 table on Wednesday evening, and it was one which they did not pass up.
A barnstorming run from Arsenal loanee Nuno Tavares ended with the unfortunate Joao Victor prodding the ball into his own net just before the hour mark, and in the third minute of second-half injury time, Azzedine Ounahi - one of the breakout stars from the World Cup - fired home a delightful second to seal the deal.
Now boasting the 'best of the rest' label behind Paris Saint-Germain, Marseille sit five points behind the champions - whose customary domestic crown is far from a guarantee - in the runners-up spot and are one clear of third-placed Lens amid their faltering form.
Tudor may not have got off to the perfect start to life at Marseille, but there have been very few blots on the Olympiens notebook in recent weeks, as the hosts have won nine and drawn one of their last 10 matches in all competitions during a magnificent spell of form.
That hot streak included five consecutive wins at the Orange Velodrome before they were held to a 1-1 draw by Monaco in their most recent home match, but Nice will travel west with little to fear after already defeating one podium side on the road this month.
Despite doing Marseille a favour in midweek, Nice can expect no preferential treatment from Tudor's title-chasers on Sunday evening, as Les Aiglons seek to replicate their feats from Wednesday's worthwhile trip to the Stade Bollaert-Delelis.
With 57 minutes on the clock, Antoine Mendy's header towards the back post met Gaetan Laborde - who tapped home what would prove to be the game's decisive goal - but Kasper Schmeichel was a relieved man after leaving Seko Fofana's late effort to rattle the crossbar.
The new manager bounce under caretaker manager Didier Digard is still alive for Nice, who have taken 10 points from four games under the inexperienced 36-year-old, while keeping three successive clean sheets against Reims, Lille and now Lens.
A penny for Lucien Favre's thoughts as Nice thrive without him, with Les Aiglons making another charge for Europe as they lie eighth in the table, but they remain nine points adrift of Rennes in the Europa Conference League spot ahead of gameweek 22.
However, inconsistency has plagued Nice away from home - where they have won just two of their last seven top-flight contests - and Marseille eased to a 3-0 win at the Allianz Riviera earlier this season, but Digard's side have certainly tightened up at the back since then.
Marseille Ligue 1 form:
W
W
W
W
D
W
Marseille form (all competitions):
W
W
W
W
D
W
Nice Ligue 1 form:
D
L
W
D
W
W
Team News
Marseille are blessed with a fully-fit squad at the moment, and the hosts' only absentee should be Eric Bailly, who will serve the sixth of his seven-game ban for hospitalising Hyeres' Almike Moussa N'Diaye with a horrendous high tackle in January's Coupe de France match.
For the time being, Leonardo Balerdi will continue alongside Samuel Gigot and Chancel Mbemba, but the Argentine also has an upcoming ban to serve for yellow card accumulation, which has ruled him out of Wednesday's cup clash with Paris Saint-Germain in Le Classique.
With no injuries to take into account, Tudor may be tempted to make a couple of alterations with PSG in mind, and Morocco star Ounahi can feel confident of breaking into the first XI after coming off the bench to good effect last time out.
Meanwhile, Nice's win over Lens came at quite the cost, as Hicham Boudaoui lasted just 21 minutes before coming off with an unspecified injury, although Digard was not overly concerned at the end of the game.
Whether the midfielder can make a rapid recovery is another question entirely - Pablo Rosario will be on standby - while Jean-Clair Todibo left the field with discomfort just before the hour mark but is not thought to be at risk of missing this one.
Nicolas Pepe, Youcef Atal and Marcin Bulka make up the rest of the visitors' absentees, and Mattia Viti will take up a place in Digard's back five if Todibo's issue is serious enough to sideline him.
Marseille possible starting lineup:
Lopez; Mbemba, Balerdi, Gigot; Clauss, Rongier, Ounahi, Tavares; Guendouzi, Malinovskyi; Sanchez
Nice possible starting lineup:
Schmeichel; Mendy, Dante, Ndayishimiye, Todibo, Lotomba; Ramsey, Thuram, Rosario, Diop; Laborde
We say: Marseille 1-1 Nice
Rearguard solidity has been the theme for Digard and his defence-heavy 5-4-1 formation, which Marseille will certainly have a hard time breaking down, despite their plentiful attacking options.