These two French top-flight heavyweights were both victorious on matchday one, with Filipe Luis and Bruno Genesio enjoying wins in their respective first league games in charge.
Amidst the backdrop of a subdued Stade Louis-II, it was the hosts who struck first through Brunner. The German rose highest in the box to meet Aleksandr Golovin’s cross from the right and powered home a header past Jeffrey de Lange.
Brunner almost netted a second when he scuffed his first close-range attempt, before forcing the Dutchman into a save with his second strike.
It was a familiar sinking feeling for a Marseille side that had lost five of their previous seven league games on their travels, but Amine Harit looked to change that particular narrative when he fired a speculative attempt wide.
The Moroccan was having an increasing influence on the match, and teed up Angel Gomes for a deflected effort which flew over the bar.
Harit was looking for a penalty as half-time approached after going down in the box with Sadibou Sane in close proximity, but referee Willy Delajod waved away those appeals.
Marseille began the second half promisingly with early chances for substitute Keyliane Abdallah and Gomes after the restart, but it was Brunner who scored his and Monaco’s second with a wonderful individual goal.
The German latched onto Eric Dier’s long ball forward, turned past Geoffrey Kondogbia, beat the defender again and manoeuvred his way past CJ Egan-Riley to fire an expertly-taken left-footed strike into the bottom corner.
Kondogbia was clearly struggling in the aftermath and was forced off soon afterwards with an apparent hamstring problem.
Les Monegasques pressed forward in a bid to rubber-stamp their victory, as Golovin’s attempted chip was kept out by De Lange, before the Dutchman was called into action again to deny Stanis Idumbo at his near post.
Marseille offered very little going forward themselves, and had nowhere near the same level of attacking threat that they exhibited in the 4-0 win over Strasbourg nine days previously.
Amine Gouiri scored twice that day, and had a rare chance to score here, only to see his close-range effort blocked.
Les Olympiens ultimately failed to turn the tide in the principality, and succumbed to successive H2H league defeats for the first time since August 2017.
It had been a bruising evening in more ways than one for Genesio’s men, with Tochukwu Nnadi and Gomes also forced off injured along with Kondogbia.
Meanwhile, this win for Luís’ team takes them to the top of the table as the only side with a 100% record after two games.
Flashscore Man of the Match: Paris Brunner (Monaco)