Halifax hit three goals in six minutes to secure a remarkable victory over high-flying Stevenage.
Craig Dobson's shot gave Stevenage an early lead, but John Martin was then sent off for violent conduct, before Steve Morison fired in to make it 2-0.
Darryn Stamp's cool finish sparked the Halifax fightback and Simon Heslop equalised with a long-range shot.
Halifax's Tom Kearney was sent off after 55 minutes but Jon Shaw headed in the winner three minutes later.
Stevenage: Julian, Nutter, Oliver, Arber, Henry, McMahon, Martin, Lewis (Molesley 73), Dobson (Batt 73), Miller (Hakim 66), Morison.
Subs Not Used: Russell, Gaia.
Sent Off: Martin (16).
Goals: Dobson 14, Morison 25.
Halifax: Legzdins, Scott (Toulson 46), Doughty, Quinn, Young, Bushell (Killeen 46), Kearney, Torpey, Heslop, Stamp (Gray 68), Shaw.
Subs Not Used: Mawson, Wright.
Sent Off: Kearney (55).
Goals: Stamp 51, Heslop 53, Shaw 58.
Ref: M Bull (Essex).