Paris Saint-Germain only needed a point at second-place LOSC in order to seal their sixth Ligue 1 Conforama title in seven seasons on Sunday night, and Thomas Tuchel's men looked to be on course when Juan Bernat cancelled out Thomas Meunier's own goal early on, but the Spain left-back was given his marching orders 10 minutes before the interval, and the floodgates duly opened in the second half.
Nicolas Pépé was Paris's primary tormenter, having been pulled back for Bernat's red card before scoring one and assisting two more as Lille went on to wrap up a 5-1 win. It was the capital club's heaviest defeat since December 2000, and Les Dogues' first five-goal haul against a league leader since May 1952.
"We played like beginners," was the exasperated reaction of 27-goal top scorer Kylian Mbappé, who had teed up Bernat's goal before injuries to Thiago Silva and Meunier had also undermined PSG's cause. "It was an end-to-end game. One moment we were in control, then we weren't. We can lose, we'll still be champions, but we can't lose like this. We need to play with more personality."
Lyon slip up
PSG will be crowned French champions with six games left to play should they avoid defeat to FC Nantes on Wednesday, although the Bretons will welcome them to their Stade de la Beaujoire with a spring in their step, having beaten Olympique Lyonnais - PSG's next closest pursuers after LOSC - 2-1 on Friday.
The teams looked to be heading for a share of the points after Kalifa Coulibaly and Martin Terrier had exchanged goals, but Anthony Limbombé curled home a stunning free-kick - his first strike for Nantes in the French top-flight - as Les Canaris put the brakes on a four-game losing streak.
"It's a brilliant victory against a great Lyon team," said Nantes coach Vahid Halilhodzic. "It's a response to the criticism we've been hearing recently and I thanked my players, told them I was proud of them." "It's a difficult spell and we just need to grit our teeth, stick together and keep working," was opposite number Bruno Génésio's response.
OM and ASSE seize chance
The result gave Olympique de Marseille and Lyon's great rivals AS Saint-Etienne a chance to further loosen Les Gones' grip on the third and final automatic UEFA Champions League qualification spot - something each of them did.
Marseille beat Nîmes Olympique 2-1 on Saturday, in what was a bittersweet victory. Mario Balotelli - scorer of seven goals in 11 games since his winter transfer from OGC Nice - limped off with a thigh injury just past the half-hour, and although his replacement Valère Germain got the south coast club on the way to victory, Rudi Garcia will be hopeful of having his star striker back for the run-in.
"He stopped because he wasn't 100 per cent," Garcia said of the Italy striker who would have been suspended for Saturday's trip to EA Guingamp anyway. "We wanted to carry on but there wasn't any point in playing a player who wasn't fully fit."
Debuchy on fire
Saint-Etienne leapfrogged Marseille on Sunday, pulling to within three points of Lyon with a 3-0 win over Girondins de Bordeaux. Right-back Mathieu Debuchy was the surprise hero of the day for Les Verts, scoring twice. Since he signed from Arsenal in January 2018, only Real Madrid captain Sergio Ramos (10) has scored more goals than Debuchy (8) among defenders in Europe's top five leagues per UEFA coefficient.
"The players showed great spirit, led by Mathieu Debuchy," enthused ASSE coach Jean-Louis Gasset. "I saw him limping and suffering, and then he came back on and scored twice. People like him are why we do this job. There are still 18 points up for grabs, and if we keep playing like that we'll progress. Let's see where we are after that."
Another six-goal thriller
Elsewhere, recent Coupe de la Ligue finalists RC Strasbourg Alsace and Guingamp also shared six goals, albeit rather more evenly than had LOSC and PSG. Le Racing needed penalties after 120 minutes of football to edge March's showpiece, but the goals were flowing at the Stade de la Meinau, Jérémy Sorbon's late leveller lifting the Bretons a point clear of SM Caen, who replaced them at the foot of the table.
Normandy club Caen were beaten 1-0 by Angers SCO on Saturday, with another former Arsenal man, Jeff Reine-Adélaïde, getting the only goal of the game. Dijon FCO complete the bottom three, their 0-0 draw with fellow strugglers Amiens SC leaving them in the relegation play-off place, a point better off than Guingamp.
Monaco holding on
AS Monaco still aren't safe. The Principality side, who took the Ligue 1 Conforama title from PSG in 2017, were held 0-0 by European aspirants Stade de Reims. Les Rouges et Blancs have improved since Leonardo Jardim returned for a second spell in the dug-out, climbing from 19th to 16th, but the Portuguese is taking nothing for granted.
"The team showed a great attitude, just as they've done over the last few games," he said "They're playing well and trying to make things happen, but the ball doesn't want to go in. There's always a foot or a save. I think our top-flight survival will be decided on the final day of the season."
Montpellier Hérault SC beat southern rivals Toulouse FC 2-1 thanks to super-sub Souleymane Camara, meanwhile, and Stade Rennais FC played out a goalless draw with OGC Nice, despite hitting the woodwork three times.