Adam Hinshelwood branded Worthing’s start at Eastbourne Town ‘unacceptable’ as they exited the Sussex Senior Cup on Tuesday.
Efforts from George Taggart and Aaron Capon inside the opening 15 minutes ensured Worthing’s two-divisions lower opposition secured a shock 2-1 third round victory.
Goalkeeper Kleton Perntreou also saved a penalty before the half-hour mark to keep the visitors in it.
And Hinshelwood felt a dreadful start cost his side their place in the Senior Cup.
He said: “We started really poorly and could have been 3-0 down inside the opening half-hour.
“The first half-hour was totally unacceptable for a club of our size.
“It’s frustrating when you’ve got a fanbase giving up their time to travel over to Eastbourne on a cold Tuesday night just before Christmas, for us to perform like we did in the first half-hour was nowhere near the expectations of this football club.
"The goals that we conceded, you can focus on us defensively, but if you’re conceding the type of goals that we are then you are always asking for trouble.
“It’s stuff you expect the players of the level we’re working at to deal with.
“We’ve got to start looking at the personnel we’ve got and they’ve got to start looking at themselves and asking if they’re good enough for where we want to be."
Worthing were much-improved after the restart but could not find a way back in.
Town had Sonny Dullaway sent off with just over 20 minutes left.
Jesse Starkey pulled one back on 81 minutes but Eastbourne held on to seal a quarter-final spot.