Brisbane - World Cup officials will meet on Sunday to review security at Brisbane's Suncorp Stadium after a fan attempted to tackle South African kicker Louis Koen in the final seconds of the Pool C match against Samoa.
The fan, his face painted in the red and blue of Samoa, charged from the stands and attempted to grab Koen from behind as the replacement flyhalf converted Neil de Kock's last-minute try in South Africa's 60-10 win on Saturday.
For his troubles, the red-faced supporter was caught by Koen's boot and knocked out cold.
The unconscious fan was taken to hospital and later released into police custody.
While the man was removed from the field by a medicab, players from both sides shook hands and knelt in prayer.
Louis Koen was unharmed.
The Australian Rugby Union issued an immediate statement: "We are obviously very concerned about the incident, it is very serious and there will be a full review of all security arrangements first thing in the morning."
"We are advised by Queensland police that the alleged offender will be charged with an offence regarding a pitch invasion.
"Security at all World Cup matches is paramount and while this is the first incident of its kind in the tournament we will be taking no chances and as a result will convene a top-level meeting in the morning to investigate and review all the circumstances surrounding the incident."
Coaches from both teams said they would not comment on the incident.
Suncorp Stadium, which had a crowd of almost 50 000 (mostly Samoan) fans on Saturday, hosts one more Pool C game between England and Uruguay on Sunday and two quarterfinals next week.
Unlike many other tournament venues, the stadium is built especially for rugby and the fans are very close to the touchline, giving stewards little chance of reacting to a determined intruder.
It's not the first time a fan has joined the action during a match involving South Africa. An enraged Springbok fan - Peter van Zyl - invaded the pitch and threw referee David McHugh to the ground during the South Africa v New Zealand Tri-Nations match in Durban two years ago. - Sapa-AFP and Reuters