Truro City manager Paul Wotton says his players learnt "a harsh lesson" as they lost 3-1 at Hayes and Yeading United.
Francis Amartey's 36th-minute opener for the hosts was cancelled out by an own goal before Hayes scored twice in the final five minutes.
The loss sees Truro slip to seventh place in the Southern Premier League's South division.
"I just think we lost too many individual battles all over the pitch," Wotton told BBC Radio Cornwall.
"It's a harsh lesson learnt today and a bit of a wake-up call for some of the lads who think they can just turn up and play football at their pace and at their tempo. That's a reality check that you can't."
The loss ended a tough week for the White Tigers which also saw them lose in the third qualifying round of the FA Cup at Taunton Town on Tuesday.
"We weren't good enough today," added Wotton.
"Sometimes you have to give credit to the opposition, Hayes were better than us, they were sharper to the ball, they were more aggressive than us and sometimes you've got to take your medicine."