Anthony Grant`s strike rescued a point for the Shrimpers three minutes from time - and made amends for his glaring first-half miss when he somehow steered the ball wide from three yards.
Grant`s angled volley cancelled out Mark Wright`s 47th minute effort, who scored his fifth goal in seven games.
Turner said: "We didn't play well, didn't pass the ball as well as we can, so I'm not convinced that we deserved to win. Like a lot of other teams that come here, the United set-up made it difficult to play through.
"It was careless to drop two points. We defended too deeply. Maybe there's a fear factor that they will get in behind us because we've only kept one clean sheet now in 14 games.
"We had a chance to get one. The upsetting thing is that the lad (Grant) got three on the back post. We shouldn't have given him the chance but I must say it was an excellent finish."
Source: PA
Source: PA