A teenager launched an unprovoked attack on another teenager he had gone to school with, knocking him unconscious.
Dale Halsall, 18, of Boardman Avenue, South Shore, pleaded guilty to assault causing him actual bodily harm.
He was bailed to December 20 for pre-sentence reports and warned he may be jailed by Blackpool magistrates.
Martine Connah, prosecuting, said the victim and a friend were walking home down Central Drive at about 3pm on November 11 when they encountered Halsall, who had been in the same year as them at Palatine High School.
The two friends were laughing and joking between themselves.
Halsall then accused the victim of laughing at him.
The victim was knocked unconscious and had to have stitches to a cut to the back of his head.
Brett Chappell, defending, asked for reports on his client.