This horrific footage of a coward’s punch was captured in Claremont early on Monday, June 5.
It shows a man in a white cap and an acquaintance approach a teenager on St Quentin Avenue about 12.30am.
They talk to him briefly, before, without warning, the man in the white hat punches or elbows the 17-year-old in the face.
The teenager is thrown backwards and is knocked to the ground.
The assailant – who is wanted by police – then jogs away with his mate without checking on the teenager. The pair was last seen heading towards Bay View Terrace.
Cottesloe Police do not know what sparked the attack but they believe it was unprovoked and the men were strangers.
“It’s a punch or an elbow to the left cheek… without provocation or warning,” Sgt Paul Gelmi said.
“There was no lead-up, they’re unknown to each other… it looks like a random attack. “It’s pretty shocking.”