STANLEY lost their 100 per cent record in disappointing style against Cambridge, who were relegated from the Football League last season.
Despite the Reds starting off well a Mark Angel long range effort was flapped at by debutant keeper Bertrand Bossu who turned it into his own net on 17 minutes.
A minute later, Cambridge were awarded a penalty when Robbie Williams pulled back David Bridges. Bridges took the spot kick and, as French keeper Bossu guessed the wrong way, his effort hit the post to the relief of the Reds.
But Cambridge were soon celebrating again when Bridges cross set up an easy tap in for Darren Quniton on 34 minutes.
Tempers then overspilled following a tackle by United's tall striker Fola Onibuje on David Brown with Michael Welch lucky to stay on the pitch after retaliating and Onibuje also only got a yellow despite the fierce tackle.
Bridges then made up for his earlier miss with the third on the stroke of half time to put the game beyond the Reds.
Boss John Coleman changed it from 4-5-1 to 4-4-2 at half-time but Brown missed an early chance before Andy Mangan grabbed a well-taken consolation seven minutes from time.
"It was a howler by the keeper and he will be disappointed with that," said Coleman. "But we know we haven't played well all season, there is no hiding from that. The lads are taking time to gel together but we will get it right."