Rennes coach Frederic Antonetti has accused Nice of "cheating" during their 1-0 defeat in Ligue 1 on Tuesday.
Antonetti claims that the penalty that his side, who were reduced to nine men in the end, conceded in the 66th minute should not have been awarded, as Yassine Jebbour's challenge on Eric Bautheac was not a foul.
"I've seen the pictures and talked to the referee," ESPNSoccernet quotes Antonetti as saying on Tuesday. "The first yellow card [that Jean Kana Biyik was shown] isn't one - it was down to cheating. The second one, perhaps, but then there wouldn't have been the red.
"And then there's Bautheac's swallow dive - the referee was conned. The pictures speak for themselves.
"Tonight, the cheats won and it disgusts me. Winning like that doesn't interest me in the slightest."
Rennes are currently six points off the final Champions League place.
