Last season’s runners-up Holbeach United were knocked out in the quarter-final at home to Division One side Olney Town on Saturday.
The Tigers went 3-1 down just before the break as Aaron Eyett’s goal looked to have put them back in the game.
Spencer Tinkler pulled one back late on but manager Seb Hayes was left to reflect on a fourth successive defeat.
He said: “The first goal on five minutes was a great strike into the top corner.
“But it came from a mistake again. Rick Drury fumbled a tame shot for a corner which we headed out but they scored from the edge of the box.
“We are getting punished and losing belief far too quickly. At the moment I’m having to lift players to turn it around but we need to make changes.
“I felt we were in the game at 2-1 but a stupid mistake gave away a free-kick and Olney got another goal just before half-time.
“It could have been a very different story at 2-1 but again I had to read them the riot act in a bid to get a response.”
New signing Dan Jenkins, who has arrived from Oakham United, is set to make his debut at Boston Town tomorrow in the Lincolnshire FA Senior Trophy quarter-final.
Hayes added: “He can play in defence or midfield and he’s very good at set-pieces. He’s a winner and his versatility will help us.”