Newport County were furious with referee Craig Hicks after Notts County scored three goals against their Welsh visitors and went top of League Two.
The Exiles had Dan Butler sent off just after the half hour when the score was still 0-0.
That decision changed the game and Notts County went ahead two minutes later.
Butler was dismissed on a straight red card after Hicks decided he had elbowed Matt Tootle in an aerial challenge.
“The referee got it wrong,” said Newport manager Michael Flynn. “That changed the game and spoiled the game.
“I’ve been told by the fourth official that Butler went in with excessive force.
“I don’t think the referee had control of the game to start with.
“He made honest decisions, but unfortunately got a lot of key ones wrong.”
Newport started strongly in the opening 30 minutes and Flynn said: “We were slightly the better team at that stage, we were getting crosses in the box.
“Even after we were down to 10 players we were played some outstanding football.
“I’m proud of the players. They kept going and it’s unfortunate the game was spoiled.
“And, just to rub salt into the wounds, I’ve watched the third goal again as well and it wasn’t over the line. It’s not been a great day.”
Notts County went top of League Two thanks to winning a game which turned in two first half minutes.
Butler was sent-off and then Jorge Grant to give Notts County the lead. There was only one goal in it at half-time, but Shola Ameobi (52 mins) and Grant (55) completed the scoring.
Flynn’s team can now put their League Two promotion ambitions to one side for a week or so. They are at home against League One Walsall in the FA Cup next Saturday, while they then take on Cheltenham Town in the Football League Trophy on the following Tuesday.
The Exiles then have a third successive home game when they take on Port Vale in League Two. That fixture is on Friday, November 10.
Notts County: Fitzsimons, Tootle (Hunt 80), Duffy (Walker 79), Brisley, Dickinson, Hawkridge, Yates, Hewitt, Grant, Stead (Forte 84), Ameobi.
Subs not used: Alessandra, Pindroch, Smith, Jones.
Newport County: Day, White, Rigg (Barnum-Bobb 46), Demetriou, Willmott, Tozer, Bennett, Dolan, Butler, Nouble (Reynolds 73), Amond (McCoulsky 46).
Subs not used: Jackson, Owen-Evans, Quigley, Bittner.
Referee: Craig Hicks.
