Guernsey FC dropped into the bottom three of Isthmian League Division One South after a 5-2 loss at Corinthian Casuals on Tuesday.
It was the side's 12th straight away defeat, with the club having not won on the road since 12 December 2015.
The Green Lions conceded three goals in the final 15 minutes of the first half and were 4-0 down with 15 minutes left.
Ross Allen scored two late goals before Casuals got their fifth in stoppage time to move up to second place.
"We were in control and then bang, bang, bang we make three awful team decisions, awful team errors, which cost us ultimately," manager Tony Vance told BBC Radio Guernsey.
"The three goals we gave away weren't great by any stretch of the imagination and just typical of us at the moment.
"From a tactical point of view, from an application point of view, everything else was looking fine, but before you know it you're out of the game and that's so frustrating."