Nabil Fekir netted an injury-time free kick as Lyon landed a 3-2 win over Monaco and a major blow on the visitors' hopes of catching Ligue 1 leaders Paris St Germain.
Monaco twice came from behind to reach half-time at 2-2 -- Adama Traore's unstoppable thunderbolt the pick after efforts from Mariano Diaz, Rony Lopes and Fekir.
The hosts had also hit the post on three occasions but were heading for a solitary point until Fekir stepped up and bent his 25-yard shot into the bottom corner in the fifth minute of added time.
PSG therefore retain their three-point lead at the summit and can double it on Saturday against Dijon.
Lyon had Monaco on the ropes from the opening moments, denied by the woodwork twice in the first 10 minutes.
Lucas Tousart was first to see his header come back off the post before Diaz suffered the same fate. The latter did not have long to wait for another chance, though, and this time did not miss with an opportunistic finish from close range.
Fekir dashed to the byline and clipped the ball powerfully across the six-yard box.
Goalkeeper Danijel Subasic tried and failed to intercept, as did Terence Kongolo at the far post, where Diaz had worked just enough space to get a decisive touch.
Monaco's response took only a few minutes, Balde Keita catching out the home defence with a perfectly-weighted pass through the middle.
Lopes picked the ball up, carried just inside the box and finished with a precision effort.
The pendulum swung again after just 23 minutes, Lyon reclaiming the lead. Ferland Mendy began by carrying the ball over halfway and, after three snappy passes upfield, was on hand to provide the final ball into the box. Kongolo again failed to sense the danger quickly enough and Fekir sent a low shot beyond Subasic.
As before, Monaco refused to stay behind for long and levelled for a second time in the 34th minute. Lopez battled well to poke the ball back to Traore from a crowded box, and the Malian smashed a shot which crashed into the roof of the net in the blink of an eye.
Diaz missed two great chances to give his side a deserved winner in the second half, including a free kick which made it a hat trick of efforts against the frame.
But when Fekir tried his luck with seconds left on the clock, he produced the magic touch.
Lyon struck in each half through Nabil Fekir and Mariano to register a 2-0 Ligue 1 victory over Marseille that leaves them trailing second place Monaco on goal difference.
Neymar scored twice as 10-man Paris Saint-Germain asserted their dominance over reigning Ligue 1 champions Monaco with a 4-1 victory at Rennes.
Monaco made the most of their Friday night fixture as they closed to within six points of Ligue 1 leaders PSG with a 4-0 rout of 10-man St Etienne away from home.
Nantes' winning run at home was ended as Mario Balotelli's 75th-minute winner completed a 2-1 comeback victory for Nice.
Runaway Ligue 1 leaders Paris Saint-Germain got back to winning ways with a 3-1 victory over struggling Lille.
Florian Thauvin's first-half penalty rescued a point for Marseille as they were forced to settle for a 1-1 draw at Montpellier.
Radamel Falcao scored his first Ligue 1 goal in more than a month to end defending champions Monaco's bad patch with a 1-0 win over Angers.
Paris Saint-Germain suffered their first defeat in 22 games in all competitions since signing Neymar this summer by falling 2-1 at Strasbourg on Saturday.
Neymar's fine strike helped Paris St Germain secure a 2-0 win over Troyes to move 10 points clear at the top of Ligue 1.