Ryan Donnelly's brace proved in vain as 10-man Airdrie crashed to a defeat against Brechin.
Brechin went ahead after 39 minutes, James Lister prodding home Charlie King's cross, but John Boyle almost equalised seconds after the restart as he headed against the crossbar.
Things got worse for United as Rhys Devlin was dismissed for a professional foul five minutes later for hauling down Lister, but they equalised 20 minutes from time when Donnelly curling into the bottom corner.
Paul McManus restored Brechin's lead 10 minutes later, drilling into the top corner, and David McKenna added a third eight minutes from time after slotting home Derek Carcary's centre.
Donnelly gave Airdrie hope a minute later by volleying in a Jamie Bain cross, but Brechin held on.
Airdrie Utd: Fairley, Bain, Lilley (Devlin 44), Stallard, Lovering, Johnston (Owens 54), Lynch, Stevenson, McLaren, Donnelly, Boyle (Keast 67). Subs Not Used: McKane, Morton.
Sent Off: Devlin (51). Booked: Lovering.
Goals: Donnelly 69, 83.
Brechin: Nelson, McLean, Dunlop, Buist, Smith, David Crawford (Carcary 72), Molloy, Brady, Hodge, King (McKenna 56), Lister (McManus 71). Subs Not Used: Scott, McClune.
Booked: Lister, McManus.
Goals: Lister 34, McManus 79, McKenna 82.
Ref: Kevin Clancy