Jason Byrne was Bray Wanderers' hero as he grabbed a late winner in the Airtricity League Premier Division basement battle at Gortakeegan.
Having failed to make the most of their chances, the visitors finally got the goal their play merited in the 86th minute.
United had Keith Quinn dismissed in the 68th minute and manager Roddy Collins was also sent to the stands.
Chances were at a premium in a tight first period. What was created came the way of the Seasiders.
John Mulroy’s hanging cross in the 21st minute saw Paul Whelan try to head clear under pressure from Waters. It fell to the waiting Byrne 16 yards out but the striker’s effort flew narrowly wide.
Then on the stroke of half time, Bray went close again.
Quigley’s quick throw saw Byrne lay the ball off to Mulroy. He played in Waters but the young attacker curled wide of the far post.
With Knight the supplier early in the second half, Byrne failed to make the most of the opportunity as he fired wide from eight yards.
Then on the hour, after good work initially by Kieran Marty Waters, Dane Massey dug out a snap shot on the turn that flashed just wide.
United's red card hoodoo struck again in the 68th minute.
Just back after serving a ban, Quinn was sent off for a tackle on Bray's Dave Webster.
To compound matters, Roddy Collins was ordered from the dug-out by referee Rob Rogers for protesting the decision.
After that it was always going to be hard for Mons to hold on and with four minutes to go Adam Hanlon's quick corner allowed Kevin Knight to whip in a left-wing cross.
It came to Byrne who steered in his fifth goal of the season with a fine header.
Monaghan United: Michael Schlingermann; Paul Whelan, Shaun Maher, Conor McMahon, Darragh Reynor; Stephen Maher (Owen Humphrey 65 mins), Robert Bayly (Willo McDonagh 64 mins), Keith Quinn; Jordan Keegan; Tony Griffiths, Conor Murphy (Danny McGuinness 52 mins).
Subs not used: Roddy Collins, Jason Marks, Bobby Ryan, Conor Forde.
Sent off: Quinn 68.
Bray Wanderers: Darren Quigley; Dave Webster, Danny O’Connor, Pierce Sweeney, Kevin Knight; Adam Hanlon, Dean Zambra, Dane Massey (Anthony Bolger 85 mins), John Mulroy (Sean Houston 78 mins), Kieran Marty Waters; Jason Byrne.
Subs not used: Adam Mitchell, Stephen Last, Graham Kelly, Doyle, Brian Kane.
