He had to wait until the final competitor, American Aaron Blunck completed his last run, but Blunck fell short, posting an 84.8. Ferreira was consistently outstanding, while Wise, who won gold at Sochi four years ago, was sensational with his winning run for 97.2.
"I was giving it everything I've got, trained as hard as I can," Porteous said. "Doing the two best runs of my life back to back, that's insane."
Porteous said he had no idea his big second run score of 94.8 was coming.
"I was happy with the way I skied and that was all I can be proud of. But for the judges to reflect that, it's insane.
"I definitely try to do my own tricks that no one else is doing and really push the sport. Today I couldn't have done better."
He said he was nervous sitting at the bottom of the run with some top quality skiers to come and the risk of being bumped out of the medals.
"But I'd done as much as I could, and if that wasn't enough then it wasn't enough."
As for the future, Porteous was understandably short of ideas in the emotion of the moment.
"I honestly have no clue. I don't know what's going to happen from here. I've never podium-ed at a big event before. I guess we'll see."
Porteous punched the air in delight when he stepped onto the podium. His brother Miguel had failed to qualify for the final. However New Zealand had three athletes in the 12-man final and Beau-James Wells began with an 87.4, and came home with a 91.6 to nail fourth.
"I've been thinking about that run for about three years," Beau-James Wells said.
"When it didn't happen on the second run, it was all down to the final run. I'm unbelievably stoked I landed it."
Wells was sixth in Sochi, now fourth and he said it is "very special, just the best."
He ran up the halfpipe 15 minutes before the final began to see his brother Byron, who was counted out of the final by injury, for the second consecutive Olympics.
"That's just the sport," Beau-James said.
"Any run you could be in hospital. It's really unfortunate."
Byron Wells' last words to his younger brother? "Go for it bro. Do it for New Zealand."
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