Honestly I think that it was a deserved win already because Marseille made a really huge effort in this game. Despite playing away they didn't see it as any problem for themselves.
Marseille is by far the best away team in the league so them winning away was not such a big surprise. I agree that it was deserving win, but still they had a lot of luck too as both goals were product of Lyon's big mistakes.
It was really important to win this game to take the second position in the standings back from Lens as well. These two teams still have a similar form to each other on the recent weeks so the balances can be upset anytime again. Marseille should just focus on benefiting from the quality advantage.
Lens-Marsielle game on May 6th could decide who wins that 2nd place and direct qualification for CL. Imho, I think that Lens is in a better form at the moment and is more likely to finish 2nd, despirte Marseille objectively having stronger team.