The 24-year-old was set upon by a group of males – described as being aged about 15 or 16 and dressed in dark clothing – in Glasgow’s Queens Park on Friday night.
He was taken to the city’s Queen Elizabeth University Hospital for treatment, but has since been discharged.
Police Scotland appealed for anyone in the area who witnessed the attack, which took place at about 8.30pm, to get in touch.
Officers are also keen to trace a passer-by who is believed to have filmed the incident on their mobile phone.
Detective Sergeant Craig Muir said: “Our inquiries into this incident are ongoing.
“The area was fairly busy at the time so I would urge anyone who witnessed the incident who has yet to speak to a police officer to get in touch.
“Inquiries so far suggest an unknown member of the public was in the area at the time and may have filmed the incident on their phone and we would be particularly keen to speak to them.
“We would also be keen to speak to any passing motorists who may have dashcam footage from the area around that time.”