More on KentOnline
Tony Burman admitted Dartford were the architects of their own downfall on Tuesday night.
Leading 1-0 through Andy Pugh's eighth goal of the season, the Darts conceded on 76 and 80 minutes as Wealdstone completed a smash-and-grab raid at Princes Park.
The visitors hadn't looked like getting back in the game but they punished a bad miss by Pugh, who had an open goal to aim at and missed the ball with the score at 1-0.
Burman said: "We lost it through a lack of concentration and a little bit of sloppiness.
"We had a great opportunity to go 2-0 up and it didn’t happen but that’s no reason to lose concentration.
"We let a ball bounce on the edge of the box and haven’t attacked it. I know the conditions were windy but it’s the same for both sides.
"The big lad who’s come on (Jefferson Louis), we said ‘whatever you do, don’t let him get the ball and turn - try sending him backwards’ because he can do that. He’s an experienced older player and he’ll go to one side and shoot. He’s got a powerful shot and we paid the penalty.
"It’s a game we should win and we haven’t done it so it’s disappointing."
Dartford came into the game on the back of a 2-0 defeat at Sutton on Saturday.
Burman said: "I felt the players, on Saturday, did all right. They did OK and they just got beaten by a very good side.
"There were no issues on Saturday but on Tuesday, a lot of things that happened were caused by our own sloppiness. That’s what’s disappointing.
"We’ve been on a good run (11 games unbeaten), we lost three points on Saturday and we needed to see how we could react. I don’t think we reacted very well."