Ten-man Paris Saint-Germain blew a chance to effectively wrap up their first Ligue 1 title since 1994 on Sunday as they were held to a 1-1 draw at home to Valenciennes.
Reacting to the earlier dismissal of PSG captain Thiago Silva, the Paris club's Brazilian director of football, Leonardo, demonstrated his unhappiness with the red card by pushing match referee Alexandre Casto in the tunnel after the full-time whistle (see video below.)
Gael Danic put the visitors ahead on 17 minutes, while the Parisians' captain Silva was shown a controversial first-half red card at Parc des Princes before Alex earned Carlo Ancelotti's side a point late on.
The result saw PSG, who own a far superior goal difference to that of second-place Marseille, have their lead at the top trimmed to seven points with three games remaining, while Valenciennes stayed 12th.
The fallout from last week's ill-tempered victory at Evian left Ancelotti without first-choice goalkeeper Salvatore Sirigu and midfielder Marco Verratti, while David Beckham was also forced to watch from the stands with Thiago Motta still suspended as well.
A hamstring injury ruled out Valenciennes' top scorer Gregory Pujol, but Lindsay Rose almost gave the visitors a dream start as his glancing header from Danic's free-kick flashed just past Nicolas Douchez's far post.
Javier Pastore forced Valenciennes 'keeper Nicolas Penneteau to tip over, but it was the away side that broke the deadlock just past the quarter hour as the deputising Douchez palmed Vincent Aboubakar's 25-yard strike right into the path of Danic, who unerringly steered the rebound low into the corner.
Zlatan Ibrahimovic appeared well placed to haul PSG level after lifting the ball over the advancing Penneteau only for the Swede to try an ill-advised flick that allowed the visitors to clear.
Maxwell then fired a volley into the side netting shortly after, while Penneteau spread himself well to deny Ezequiel Lavezzi.
PSG's hopes were dealt a serious blow as Silva was dismissed three minutes before half-time following an altercation with referee Alexandre Castro in which the Brazilian placed his hands on the official, who appeared to tell protesting teammates he had been pushed by the defender.
Valenciennes' continuing quest for an unlikely win saw Kenny Lala repelled by Douchez, but it was the visitors' goal that was coming under increasing pressure as Ibrahimovic drilled narrowly wide from an acute angle before Penneteau made a vital intervention to deny Kevin Gameiro a tap-in.
Alex then had a header cleared off the line by Maor Melikson, but the away side failed to heed that warning as the towering centre-half escaped his marker to power Lavezzi's corner home seven minutes from time.
Earlier, Lyon remained on track to qualify for next season's Champions League after cruising past relegation-battling Nancy 3-0.
Bafetimbi Gomis struck two second half goals to take his season's tally to 16, while Yoann Gourcuff was also on target as Lyon recorded their third victory in four to take a three-point lead in the race for the third and final Champions League place.
Meanwhile, Nancy remain one point clear of the drop zone with three games remaining after their six-game unbeaten streak came to an end.
Nice strengthened their quest for European football next season, climbing to fourth, following a 3-0 victory at slumping Rennes.
Dario Cvitanich netted two second-half goals, the second of which came from the penalty spot, to take his haul to 17 for the campaign, while Eric Bautheac added a late third for Claude Puel's side.
Defeat for Rennes means they've now just won once their last 11 outings, a slide that has seen the League Cup runners-up drop from fifth down to a disappointing 11th.