But within six minutes, it was all over. First, Zlatan Ibrahimovic accidentally deceived the Marseille defenders, slipping as he took a free-kick, and the loose ball was stabbed high into the net. Two minutes later Javier Pastore flashed in a low cross and Marseille keeper Steve Mandanda was left stranded as the ball was deflected in for PSG’s winner.

One miscue, one own goal. A match turned on its head and 65,000 voices strangled into unbelieving silence.

It will be cruel if Marseille’s title challenge is now snuffed out, especially as they have done so well to match PSG stride-for-stride, but in the end, their defeat would’ve been heavier but for two fine saves by Mandanda.

As it is, all the top four, including Monaco who play tonight and Lyon, are still in with a shout because PSG have a testing few weeks ahead, starting with a cup semi-final tomorrow, then the league cup final on Saturday night, followed by matches home and away against Barcelona.

PSG have strength in their squad, but this run of games asks a lot, especially as two of their important players, David Luiz and Thiago Motta, both Champions League winners, went off with hamstring injuries on Sunday.

This season could go down as a turning point for the French, because they have two clubs in the last eight of the Champions League for the first time since 2010 and also because they have got there by defeating Premier League opposition. Even if PSG and Monaco should now fail they have put down a marker, and it is a marker that the top men in French football are determined to hammer into place. In the process it seems they are ready to let their weaker rivals go to the wall.

Clubs such as PSG, Monaco, Marseille and especially Lyon, with their powerful chairman Jean-Michel Aulas in the lead, want a single league authority to run the game. They want a strong commercial operation, along Premier League lines, as opposed to the competing bodies that at exist at present, reducing the authority of the French FA and eliminating, or emasculating, the Union of Professional Football Clubs (UCPF).

The UCPF is their big obstacle. As an employers’ association, it has legal standing, governed by a two-thirds majority. It includes second and third division clubs whose fragile finances could be wrecked if rich clubs get their way. Rich clubs whose agenda includes ditching the league cup and reducing the top division to 18 clubs. They are manoeuvring for change in advance of a meeting in June. But they can’t move too far or too fast, because French law gives both players’ representatives and educational bodies a say.

“The hottest topics won’t be addressed,” says Guincamp president Bernard Desplat. “From an economic point of view we’re amateurs compared to other European leagues.” The question is how long Lyon, PSG and the rest will wait.