A teenager waiting at taxi rank in Busselton has been set upon by a man, who beat him and then fled in a taxi.
A 19-year-old man was waiting had been waiting at the taxi rank on Queen Street for about five minutes, when three men approached him at 1.30am and struck up a conversation.
Unexpectedly one of the men punched the victim to the face, knocking him unconscious.
All three offenders left the scene in a taxi.
The victim was taken to Busselton Hospital for treatment before being released.
A 19-year-old man is in custody and is assisting police with their inquiries.
Anyone with any information is asked to contact Crime Stoppers on1800 333 000.