Horsham head coach Nick Stocker was disappointed his side failed to beat Hove, despite holding a big 28-10 lead in the closing stages.
Hove eventually won 32-28 at the fifth attempt in a dramatic local derby in London 2 South East at Hammerpond Road.
But Stocker pointed to his side’s relative inexperience as they allowed their emotions to spill over in a frantic end to the match during which they conceded four tries to lose the local derby battle.
He said: “It was frustrating as we had a healthy lead but we could not close the game out.
“We lost our discipline and had two players sin-binned for the last 13 minutes and it counted against us. We switched off and it cost us the game.”
Hove scored an early try with a ball spun wide following a driven line-out, but Horsham responded with three tries in the space of five minutes to take a commanding 21-5 lead into half-time.
Nick Bell touched down following a drive off a line-out, Joe Wilde attacked the space to score from 30 yards after some fine multi-phase play with numerous hands involved. Tom Johnson converted both tries from close to the touchline.
Following pressure from the kick-off, George Palmer broke down the wing to ground the ball in the corner but a high tackle resulted in a penalty try converted by Tom Johnson.
Horsham were affected by Johnson going off injured at half-time and Hove opened the scoring with a contested try after winning the footrace following a chip over the top which Nick Bell appeared to have grounded first.
Multiple phase pick-and-go play led to Johnny Ordidge powering through to score on 46 minutes, converted by Will Bell, with Horsham taking a 28-10 lead.
But those were the last points Horsham were to score as they were disrupted by injury, and missed a couple of straight-forward kicks at goal to build an unassailable lead.
Hove then came back to score four well-taken tries with the final score coming in the last minute of the match.
In their desperate defence, Horsham were hampered by yellow cards to Johnny Whiting and Emmet O’Rahilly and in a dramatic finale, played the end of the game with 13 players.
Stocker added: “One of their tries was dubious as the referee was unsighted and we got to the ball first, so this should not have been awarded.
“It was fraught at the end - Hove are a good, experienced team and were absolutely desperate to win the game.
“We have an average age of 22 and are still learning. We have already been working hard in training this week and will get them next time!”
The Green and Whites now have two free weekends ahead of returning to league action on Saturday, January 7, with a trip to Bromley.
Horsham: N.Bell, Fisher, Barber, Whiting, Clarkson, Smith, O’Rahilly, Tredgett, J.Johnson, T.Johnson, Palmer, Ordidge, Wilde, J.Bell, W.Bell. Subs: Conzague, Plumpton, Goward.