Police were called to Colwick Woods Field, off Greenwood Road, after an elderly man suffered a fractured eye socket when he was punched in the face.
His dog had earlier been attacked by another dog and a brief verbal altercation took place between the victim and the other dog owner.
A witness, who was walking with her partner, called police after seeing the punch being thrown.
The 70-year-old victim also needed stitches for a cut to the eye after the attack at around 12noon on 2 March 2023.
Detectives have been carrying out a detailed investigation into the incident and arrested a 41-year-old man on suspicion of assault occasioning grievous bodily harm with intent in the early hours of Thursday (4 May).
Detective Sergeant Chris Mavers, of Nottinghamshire Police, said: “This was a nasty, unprovoked attack on a pensioner and we were determined to find the man responsible and bring him to justice.
“We have been working hard on the investigation and I’m pleased we have been able to locate a suspect through intensive inquiries and despite the lack of CCTV covering the area where the attack took place. I’m very grateful to the witnesses who stopped to help the victim and call police.
“This arrest is an important step but our investigation remains ongoing.”
Anyone with any information should call Nottinghamshire Police on 101, quoting incident number 296 of 2 March 2023, or Crimestoppers on 0800 555111.
