Wayne Andrews scored his 11th goal of the season for Colchester United, but it was not enough to give the Essex club victory following a 1-1 draw with Barnsley at Layer Road.
Andrews, without a goal in the previous nine games, returned to form with the opener on 25 minutes.
It was a blunder from keeper Sasa Ilic, who scurried to the edge of his box to intercept a long ball over the top from Colchester skipper Scott Fitzgerald. However, he appeared to dive too soon and the ball eluded him, giving Andrews the simple task of threading the ball into an unguarded net.
Barnsley did not level until the 78th minute, when Kevin Betsy turned to fire home from just inside the box.
And tempers boiled over when Colchester's Karl Duguid was sent off by referee Clive Penton for a professional foul in the 81st minute.
It appeared to be a very harsh decision and, although Betsy was clean through on goal, there was no real contact as the Barnsley man fell under Duguid's challenge.
Referee Penton chose to show Duguid the red card. It had been a terrible time for Duguid, Colchester's longest serving player, because he was also sent off for violent conduct at QPR two weeks earlier.
His three-match suspension for that dismissal kicks in against Accrington in the FA Cup replay on Tuesday night.
The U's will rue an earlier miss from Scott McGleish, who fired over the top from just six yards out following Greg Halford's cross midway through the second half when the score was 1-0.
McGleish's miss was a turning point.
Colchester manager Phil Parkinson said: "We didn't play that well, but it was a good point.
"I thought the sending off was a ridiculous decision. I've just seen the video and Karl Duguid did not even make contact with their player.
"I'm hoping to appeal against the decision."