The Hawks slipped to a second defeat inside three days as league leaders Braintree Town came from behind to win 2-1 at West Leigh Park.
The hosts took the lead with just three minutes on the clock when Jon McDonald headed home Sammy Igoe’s cross.
But the game turned after the break as Braintree equalised when Jake Newton’s clearance struck Cliff Akurang and went into the net.
The away side then bagged their winner after substitute Scott Shulton’s quickly-taken shot from the edge of the area beat Nathan Ashmore.
In the final minutes, the Hawks had McDonald controversially sent off after clashing with Akurang, although the defender seemed to make minimal contact, if any.
Meanwhile, an injury-time winner denied Fareham a place in the Russell-Cotes Cup semi-final as they slipped to a 2-1 loss to Totton & Eling.
The Reds looked to be heading into extra-time after Mark Cotton’s leveller, only for the visitors to steal it with seconds remaining.