Watford manager Walter Mazzarri claims that there were two fouls in the build-up to Chelsea's winner in the 4-3 result at Stamford Bridge.
The Hornets had done well from being 3-1 down to draw the score level, but Cesc Fabregas' 88th minute winner eventually proved to be the difference between the two sides.
"When a manager loses a game like this, and we lost others as well during the season in this way, they say he is unlucky and tries to find excuses, but you saw how the game went," Mazzarri told Sky Sports.
"There were two fouls [for the fourth goal]. One on [Tom] Cleverley, and another on [Etienne] Capoue. And we were unfortunate because we could have scored before then with [Valon] Behrami and [Daryl] Janmaat, and these decisions made us lose the game."
