Tonga league star Eli Katoa has successfully undergone surgery after “suffering seizure activity” on the bench during the second half of Sunday’s Pacific Championships match between Tonga and New Zealand.

Katoa was seen slouching in his seat minutes after coming off the field following his third head knock of the afternoon, which prompted his teammates to alert medical staff he was unwell.

He was fitted with an oxygen mask before being put on a stretcher and taken away on a medi-cab, while also covering him with a team jacket.

He was taken to hospital and his NRL club, the Melbourne Storm have provided an update saying he is now in a stable condition after undergoing surgery.

“Melbourne Storm forward Eli Katoa was taken to hospital after suffering seizure activity on the bench,” said a Storm spokesperson.

“Eli underwent surgery overnight and is in a stable condition being supported by his partner and mother.

Medical staff attend to Eli Katoa. Photo / NZ Herald.

“Storm medical staff remain in close contact with the hospital and Tonga’s team Chief Medical Officer.”

Katoa provided an update on his Instagram page, saying: “Appreciate everyone for checking in, sorry if I haven’t got back to any of you guys, bit I really appreciate all the love and the messages.”

The 25-year-old’s first knock came in the warm-up when he was on the wrong end of an accidental but nasty looking hit from teammate Lehi Hopoate as the two contested a ball, but was passed fit to play.

Katoa than copped an accidental elbow from a teammate in the 10th minute and came off for a HIA but passed that and returned to the game.

In the second half, his day was officially done when he got caught in an awkward position trying to make a tackle and came off second best.

Post match, Tonga coach Kristian Woolf insisted the correct medical practices were taken following the incidents.

“Obviously it wasn’t great on the sideline,” Woolf said. “I don’t know the full details of it.

“The doctors have gone with him. But he wasn’t great on the sideline and, I’m told that he was responsive and was improving before he actually went to the hospital.

“We got two very experienced doctors there. They’ve done the usual HIA. He’s passed all that well.

“My job’s not to question doctors. They’re both comfortable with that and comfortable with him coming back onto the field.

“I don’t think there’s anything to worry about there in terms of the process. Unfortunately, I think he’s copped a second hit that’s quite heavy and there’s been a bit of a poor result on the back of that.”

The incident capped off a tough night for Tonga, as they went down 40-14 to the Kiwis in front of 38,000 fans at Auckland’s Eden Park.

The Kiwis outscored Tonga seven tries to two, with Dylan Brown claiming a brace and assisting two more.

The Kiwis will face Samoa in the Pacific Cup final next Sunday in Sydney.

Ben Francis is an Auckland-based reporter for the New Zealand Herald who covers breaking sports news.