A police officer was attending an incident at Whanganui address when he was king hit in the line of duty.
Madison O'Hagan-Laing got into a crouch position, clenched his hand into a fist and launched at the officer.
O'Hagan-Laing appeared in Whanganui District Court this week for sentencing and Judge Charles Blackie said the strike was of such force that it knocked the officer to the ground.
"For a short time he lost consciousness and later he was diagnosed as having a broken nose, I'm told a fractured cheekbone, a black eye and severe swelling to his face," the judge said.
"I have to say that the court normally takes a fairly dim view of assaults on police."