The man was punched after becoming involved in an argument with his assailant around 4.20pm, about 15 minutes after the last race had ended.

Police say the man hit his head as he fell to the ground.

He was treated by onsite paramedics before being taken to Wollongong Hospital in a critical condition.

The identity of the man’s attacker remains unknown and police have appealed for witnesses to come forward.

Turf club chief executive Peter De Vries labelled the incident “extremely unfortunate” and said the best wishes of every one at the club were with the victim and his family.

“People come to the races to have an afternoon’s enjoyment and to have it interrupted this way is extremely sad,” he said.

“This type of behaviour is not what we want to happen when we put on a race day.”

Mr De Vries confirmed the crowd numbered about 1,500 at the race meet.

He said 17 security staff were on-site for the event, in line with the club’s liquor licensing requirements.

He also confirmed the club was working closely with police to help identify the culprit.

“I believe the police have already had a quick look at the CCTV footage but we’ll get our IT people to take out whatever it is [police] require,” he said.

Anyone with information is urged to contact Lake Illawarra police or Crime Stoppers on 1800 333 000.