The Ligue 1 title race remains wide open after an entertaining and eventful scoreless draw on Sunday, which the home side thought they had won in the second half.
The Olympico stalemate saw Lyon extend its lead over second-placed Paris Saint-Germain to two points, and stay four ahead of l'OM, which had Jeremy Morel sent off.
A disciplined performance from the visitor left Marcelo Bielsa's side frustrated, but Lyon had chances to win the game as the country's top scorer Alexandre Lacazette twice wasted the sort of opportunities he was snapping up prior to a February injury.
Lucas Ocampos also had a goal controversially ruled out in the second half, with replays proving inconclusive as to whether or not his effort had crossed the line.
Bielsa showed his faith in Andre-Pierre Gignac by bringing him back into the side at the expense of Michy Batshuayi, who scored twice in a 6-1 win over Toulouse last week, and the big striker had the first meaningful chance of the game inside three minutes, cutting inside from the right to fire his left-footed shot straight at Anthony Lopes when a square pass to Andre Ayew would have been a better option.
Ligue 1's top scorer Lacazette should have opened the scoring a few minutes later when played through on goal by Jordan Ferri, but his tame effort was too close to Steve Mandanda in the Marseille goal.
A glut of goals was expected at the Veledrome between Ligue 1's most lethal sides, and Mendy wasted the third clear chance of a frantic first 13 minutes as he scuffed his shot into the ground. The last eight league games between these two had produced 33 goals, while no Ligue 1 encounter has produced more than the 89 this matchup has enjoyed since 2000.
Gignac thought he had opened the scoring on the half-hour, but a sprawling Lopes superbly tipped the striker's header wide for a corner.
Lyon did well to quell the host's Bielsa-inspired approach as the half wore on, enjoying periods of possession in which it was able to slow the tempo.
But Lyon clearly lacked a cutting edge going forward which coach Hubert Fournier sort to remedy by introducing Clinton Njie for an ineffective Rachid Ghezzal on 42 minutes.
Dimitri Payet began to get into his groove after the break, first breaking forward to almost play in Gignac before testing Lopes from long range.
With Payet more involved, Marseille picked up the pace again after the restart, but Lyon should have gone ahead after the hour when Lacazette lost the flight of a deep free kick with the goal gaping from six yards.
The chances continued to arrive as Payet flashed a volley wide from long-range before Gignac's angled, right-footed strike came back off the post with Lopes beaten.
The temperature was rising in the Velodrome with 20 minute remaining and the host thought it had won the game when Ocampos appeared to have bundled home a winner. Lopes clawed it out and replays proved inconclusive as to whether the whole ball had indeed crossed the line.
Jeremy Morel was then dismissed with five minutes to go as the game threatened to boil over, receiving a straight red card for a lunge at Maxime Gonalons.
Mandanda then rescued a point Marseille with a wonderful, diving save to tip a low Corentin Tolisso shot around the post.