The France striker lasted a little over half an hour before limping off close to tears
Paris Saint-Germain suffered a major injury blow when striker Kylian Mbappe was forced off with an ankle injury during the first half of their Coupe de France final against Saint-Etienne.
Mbappe was left in agony after being scythed down by a sliding challenge from Saint-Etienne defender Loic Perrin as he looked to run through on goal.
Replays showed Mbappe's right ankle was bent inwards by the tackle, which sparked a furious melee between both sets of players, with even Saint-Etienne goalkeeper Jessy Moulin running out of his penalty area to get involved.
Mbappe, meanwhile, was left writhing in pain on the turf as the PSG's medical team sprinted onto the pitch to assess the damage.
After several minutes of treatment, the 21-year-old limped off the field still in obvious discomfort and looked close to tears as he headed straight down the tunnel, with Pablo Sarabia coming on his place.
Perrin was initially booked for the challenge but after consulting the VAR monitor, referee Amaury Delerue decided to upgrade his punishment to a red card, the third time Saint-Etienne have had a player sent off in the first half in a game against PSG this season.
PSG also lost defender Thilo Kehrer to injury during the opening 45 minutes, with Colin Dagba coming on in his place.
Mbappe had earlier played key role in PSG's opener, with his fierce shot parried by Moulin into the path of Neymar, who smashed the rebound in off the bar from close range.
Seven minutes of time was added on to the end of a fractious first half which saw seven yellow cards alongside Perrin's red, once of which was for PSG substitute Marco Verratti for arguing with the referee as he went to check the VAR monitor.
Though the severity of the injury is yet to be known, Mbappe's participation in PSG's remaining fixtures this season could now be in doubt.
Thomas Tuchel's side face Lyon in the Coupe de la Ligue final next week before a huge clash against Serie A outfit Atalanta in the quarter-finals of the Champions League in Lisbon on August 12.