Paul Tait said an uncharacteristic lack of ruthlessness in front of goal cost his Everton Under-18s team after they were edged out 1-0 by Liverpool at USM Finch Farm.
The Toffees were the more progressive team for large periods but a 30th-minute strike from Jack Bearne saw the away side escape with three points.
Everton slip to fourth in the U18 Premier League (North) table with three matches left to play.
The young Blues are the top goalscorers in the division, but boss Tait said his team lacked a clinical edge in the derby clash.
“We’re bitterly disappointed,” he said.