Canberra’s 33-26 defeat of South Sydney has been overshadowed by a worrying medical incident involving Raiders forward Corey Harawira-Naera, who collapsed on the ground mid-game and began experiencing a seizure.

Harawira-Naera, who had been limping in backplay, appeared disoriented as he returned to position for a line-dropout and then collapsed on the ground in the 65th minute.

The 28-year-old began convulsing as medical staff rushed to attend to him.

Players provided a shield as medical staff worked on the New Zealand international, who was responsive and conscious when moved onto a medicab.

Play had stopped for more than 10 minutes by the time he was taken from the field to a standing ovation.

Harawira-Naera left Accor Stadium in an ambulance with his sister, who had been attending the game, by his side. 

Raiders staff were still piecing together the incident at full-time.

“They’re not sure of why the seizure occurred,” coach Ricky Stuart said.

“They’re situations that are very uncommon and they’re scary. It’s one of your mates. It makes it even harder.

“When it’s one of your own, you just can’t stop thinking, ‘Where is this going?’. The seizure lasted a good 30 seconds by the look of it.”

Rabbitohs five-eighth Cody Walker, the best player on the field in a beaten side, was left shaken by the incident.

“It’s not something you want to see on the footy field,” he said.

“We go to battle … we want to hurt each other in a clean way but you never want to see a player like that.

“On behalf of everyone here at the club, we just want to send our thoughts and prayers to his family.”

Canberra’s Josh Papalii and Jack Wighton took starring roles in Saturday’s chaotic win, vindicating their sudden State of Origin retirements.

The pair would have been firmly in the frame for selection in this year’s series before their sudden withdrawals to focus on the Raiders. 

They will be at peace with that decision after they helped their side withstand three injuries and a Cody Walker master-class to consolidate Canberra’s spot in the top eight.

As well as the loss of Harawira-Naera, the Raiders had earlier been forced to overcome a knee injury to fullback Seb Kris and lost Jordan Rapana to a concussion in the final 10 minutes.

The absences of Origin contingent Latrell Mitchell, Jai Arrow and Cameron Murray, as well as injured leading try-scorer Campbell Graham, looked to have thwarted Souths early.

Papalii and Corey Horsburgh teamed up to help the Raiders put on three tries in 10 minutes and more first-half points than the Rabbitohs have conceded all season (18).

But Souths weren’t out of the fight as Walker sparked their attack, the league’s leader in try assists coming with three more on the back of his trademark passing game. 

Walker had a fourth off the boot, sending Damien Cook over in the 68th minute with a grubber kick that allowed the hooker to bounce back from his surprise Origin omission.

Just as Walker was working to prevent a Raiders boilover, Wighton turned it on in his first game against Souths since signing a long-term contract to join the Redfern club from next year.

He sent a bullet pass to Jarrod Croker on the left that allowed the Raiders to regain the lead through Tom Starling.

Albert Hopoate had his third try, and the match-winner, directly after Wighton broke through the defence in the 73rd minute.

“Jack showed his class there at the end of the game,” Stuart said.

“That’s a big win, coming back from the adversity we faced.”

By Jasper Bruce in Sydney