Guernsey FC boss Tony Vance was disappointed with his side's showing despite their 2-0 win over Feltham.
Striker Ross Allen grabbed both goals as the island side stay 11 points clear at the top of the Combined Counties League Division One.
"The performance wasn't there, we were flat," Vance told BBC Guernsey after a record crowd of 1,752 saw the game.
"It is disappointing really because the occasion warranted that we put a decent performance," he added.
Vance said the side's showing fell underneath the level he expects his side to play.
"I've got high standards, they've got high standards.
"It was lovely opportunity to play good football, and whilst you've got to give credit to the opposition because they didn't let us play and had some tactics that we fell into, I'm just disappointed because I like to be entertained as well," he said.