Newport boss Justin Edinburgh cut a frustrated figure after two late goals saw his side lose 2-1 at home to AFC Wimbledon.
The Exiles looked to be moving to within four points of the play-offs when goalkeeper Ross Worner dropped the ball into his own net in the 65th minute.
But goals in the 85th and 88th minute respectively from substitutes Charlie Sheringham and Kevin Sainte-Luce sealed all three points for the visitors.
And that meant Newport, who slipped to their second shock home defeat in the space of four days after Saturday's loss to Cheltenham, fell to ninth place in League Two, seven points adrift of seventh-placed Southend.
Edinburgh said: "Probably in the end AFC Wimbledon deserved to win the game.
"We are bitterly disappointed because we are not quite reaching the high standards that we have set at the moment.
"We looked a bit tired at times but we are not going to use that as an excuse. At the moment we are just not performing.
"It looked like it was going to be one of those games where we get a bit of luck and have a scrappy 1-0 win but we couldn't see the game out.
"We would have taken that to get us back on track but we could not make the most of the opportunity that was presented to us. We are going to regret that.
"We have got another tough game at home against Scunthorpe on Saturday and we are going to have to play a lot better than that if we want to get something from the game."