Henrique fires Marseille past Lyon
Roberto De Zerbi's men have a six-point lead over fifth-placed Nice in the battle for the four Champions League places after bouncing back from last weekend's loss at Nice.
They are 10 points adrift of leaders Paris Saint-Germain.
Lyon sit seventh in the table, five points off the top four after defeat in their first game under new coach Paulo Fonseca.
"We have had only one training session," said Fonseca, who was sacked by AC Milan earlier this season.
"We showed a good state of mind and courage. We have to work a lot but I am very positive."
Marseille were on top for most of the first half but struggled to create clear-cut chances, with Michael Murillo's shot wide the closest they came.
Lyon made the hosts pay less than eight minutes after the restart as Corentin Tolisso burst into the box from midfield to finish off an excellent move from Rayan Cherki's pass.
The 21-year-old Cherki has been heavily linked with a possible move to Borussia Dortmund before the transfer window closes on Monday.
Marseille responded just after the hour, as Mason Greenwood tapped home his 13th Ligue 1 goal of the season after new signing Amine Gouiri's mishit shot bobbled across the area.
OM took the lead in the 64th minute when Adrien Rabiot headed in after Pierre-Emile Hojbjerg nodded the ball in his direction.
But France midfielder Rabiot turned villain a few minutes later as his handball conceded a penalty.
Alexandre Lacazette stepped up to slam the ball into the roof of the net, scoring for the first time since a hat-trick against Nice on December 1.
Marseille were not to be denied, though, and Henrique volleyed in the winner with five minutes remaining as he met Pol Lirola's cross completely unmarked at the back post.
Earlier, Habib Beye enjoyed a winning start as Rennes coach thanks to Ludovic Blas' late goal in a 1-0 victory over Strasbourg which moved the Breton club out of the relegation play-off place.
Nice sit one point behind fourth-placed Lille after a 1-1 draw with Toulouse.