Guernsey FC assistant manager Colin Fallaize says his side have got to learn from their first ever defeat in the Combined Counties League.
Guernsey lost 2-1 at Spelthorne Sports to end an 11-match unbeaten run as Ross Allen got the Green Lions' only goal.
"It was a day that we've got to move on from and definitely learn a great deal from," Fallaize told BBC Guernsey.
"We were up against an opposition that were more up for it and were showing a lot more desire all round," he added.
"The boys that were involved were extremely disappointed but nothing in life is easy and you've got to work for it," Fallaize said.
"One of the things that certainly was clear to me, and it has been clear to me for a few weeks, is that people are really stepping up their game and intensity levels when they face us," he added.
"If Guernsey FC wants to go forward it's got an awful lot of learning to do and an awful lot of hard work to keep up," Fallaize said.
Guernsey are still top of the table, but their lead has been cut to three points.