Neymar has been sent off and then tried to confront a player after the game as defending champions Paris Saint-Germain lost 1-0 at home to Lille, falling three points behind the new Ligue 1 leaders in a tense title race.
PSG are only one point ahead of Monaco, who earlier on Saturday beat Metz 4-0 to take third place.
Lyon are fourth after drawing 1-1 at Lens.
Neymar was shown a second yellow card in the 90th minute for kicking right back Tiago Djalo off the ball, having been booked in the first half for shoving midfielder Benjamin Andre in the face.
Djalo was also sent off for the late incident involving Neymar, remonstrating angrily with the referee.
As both players argued walking back to the locker rooms, footage from broadcaster Canal Plus captured Neymar pushing Djalo on the shoulder and then trying to get past some security officials to confront him.
An angry Djalo also reacted, trying to reach Neymar, causing one security official to fall over, while another intervened swiftly to block Neymar and lead him away.
Jonathan David scored Lille's goal in the 20th minute with a slightly deflected strike, as PSG slipped to a fifth home defeat and eighth overall in the league.
Frustration got to Neymar, who now faces another suspension after getting red-carded against Marseille at the start of the campaign.
Shortly after shoving Andre in the face, he fell to the ground in a failed bid to win a penalty.
Starting his first game for two months after recovering from a torn adductor muscle, Neymar was wasteful.
Lyon grabbed a share of the points in their clash at Lens with midfielder Lucas Paqueta equalising in the 81st after right back Jonathan Clauss struck midway through the second half for the hosts.
Monaco, who have now lost only once in 16 league games, struck a double blow early in the second half against Metz.
Cesc Fabregas scored a penalty in the 49th minute after forward Stevan Jovetic was fouled, and striker Kevin Volland finished confidently two minutes later from Belgian midfielder Eliot Matazo's pass.
Striker Wissam Ben Yedder was surprisingly left on the bench but came on to notch a fine third when he cut inside a defender and thumped the ball under the crossbar in the 76th.
Ben Yedder was fouled by central defender John Boye and took the penalty to round out the scoring in the 88th.