About 7.30am on March 16, Jenner was walking on Ranolf St with his partner who was pushing their son in a pram near Kuirau Park, the summary of facts provided to the Rotorua Daily Post stated.
The victim gave a wide berth as he biked past the pair on the shared pedestrian and cycle path.
Jenner's partner began to verbally abuse the victim for being on the footpath, to which an argument started about it being a shared pathway.
Jenner defended his partner and then aggressively approached the victim. The victim put his arm up to defend himself and accidentally bumped Jenner, it stated.
He pushed the victim off his bike, causing the victim to dislocate his thumb as he hit the ground.
Jenner then began punching the victim in the head multiple times with a closed fist while he lay on the ground before pushing him into the bonnet of a car and fleeing through Kuirau Park.
The victim suffered a dislocated thumb, a black eye, several scratches, swelling to his face and a sprained ankle.
Jenner told police that the victim had assaulted him first.
He and the victim were not known to each other.