Angel Di Maria scored twice in three minutes either side of half-time as holders Paris Saint Germain booked their place in the semi-finals of the Coupe de France.
The French giants revealed just before kick off that Neymar will undergo surgery in Brazil on his fractured foot, ruling him out of next week’s Champions League last-16 second leg tie against Real Madrid.
PSG made eight changes from the side that beat their bitter rivals in the league on Sunday but they were still too strong.
Di Maria’s deflected effort just before the break put the home side ahead in the quarter-final tie on Wednesday night.
Kylian Mbappe was substituted at half-time after suffering a knock.
The Argentine doubled his side’s advantage three minutes into the second-half when his side-footed effort was deflected under the hand of the keeper.
Edinson Cavani sealed victory with a neat finish in the 81st minute.
It was PSG’s second emphatic victory over Marseille in three days after a 3-0 league win on Sunday in which their Brazil forward Neymar suffered a broken that requires surgery and is likely to keep him out for six to eight weeks.
Di Maria, whose playing time this season has been limited by Neymar’s performances, scored both goals with his weaker right foot, rifling in the opener on the stroke of halftime and adding the second in the 48th minute.
Striker Cavani sealed the rout with a thumping finish eight minutes from time after a dazzling move which underlined the home team’s domination, with Marseille goalkeeper Steve Mandana sparing the visitors from a heavier defeat.
PSG manager Unai Emery had earlier suggested there was a ‘small chance’ Neymar may be able to feature in next Tuesday’s Champions League last-16 second leg against Real Madrid. But that is no longer the case.
PSG, who trail Real 3-1 after the first leg in Madrid, will sorely miss Neymar who has scored 19 and assisted 13 of their 84 Ligue 1 goals this season.
His absence makes PSG even bigger underdogs against Real but they should have no trouble retaining their domestic crown without him as they currently lead Ligue 1 rivals Monaco by 14 points with 11 games to play.