The Ligue 1 leaders announced on Wednesday that the world's most expensive player will miss next week's second leg of their Champions League last-16 tie with Real Madrid, which they trail 3-1, after the decision was made for him to have surgery on a cracked metatarsal.
While Neymar's prolonged absence may prove fatal to their Champions League hopes, PSG reaffirmed that it will have little impact on their domestic success as Angel Di Maria's double saw them into a fourth successive Coupe de France semi-final.
Di Maria settled the contest with a pair of deflected strikes, the first a vicious shot from outside the box, either side of half-time.
Deserved gloss to the scoreline was added courtesy of a wonderful team move finished off by Edinson Cavani, as Marseille again suffered at PSG's hands having lost by the same scoreline in the weekend’s Ligue 1 meeting, where Neymar suffered his injury.
The win keeps PSG firmly on course for a domestic treble and they will be one of just two top-flight teams in the last four after shock triumphs for third-tier Chambly and Les Herbiers, while a free-flowing second-half showing will perhaps give Unai Emery added hope they can fight back against Madrid even without their world-record signing.
PSG started very brightly and, after Yuri Berchiche had an effort beaten away by Steve Mandanda, Cavani wasted a gilt-edged chance to give them the lead.
Aymen Abdennour was then fortunate not to concede a penalty when the Marseille centre-back appeared to handle in the area.
Most of the pressing was unsurprisingly done by PSG, but Marseille remained dangerous on the counter-attack and Florian Thauvin curled an effort well over the crossbar.
Di Maria then showed Thauvin how it should be done as he bent one towards goal from the edge of the area, only to be denied by a brilliant diving save from Mandanda.
But Mandanda could not replicate the same heroics on the stroke of half-time, the Marseille goalkeeper beaten as Di Maria unleashed a fierce half-volley that took a slight deflection off Adil Rami and flew into the bottom-left corner.
Javier Pastore replaced Kylian Mbappe ahead of the restart and three minutes into the second half Di Maria effectively put the tie to bed - but in far less spectacular fashion.
Marseille failed to deal with Yuri's cross from the left, which eventually fell to Di Maria, and his side-foot effort deflected off Hiroki Saki and under Mandanda.
Di Maria then lashed narrowly wide from long range and Julian Draxler went agonisingly close to scoring one of the goals of the season as his bicycle kick from Marco Verratti's lofted pass was only just off target.
A stunning reflex save saw Mandanda keep out Pastore's diving header, but the final flourish came in style as Draxler nodded a Verratti chip down for Cavani to fire into the bottom-right corner in an illustration of the kind of football they will need to produce to deliver a Champions League turnaround next week.