porteous was selected to compete at the 2018 winter olympics, making him the second-youngest winter olympian in the nation's history (behind alice robinson). in the men's halfpipe he won the bronze medal, becoming only the third new zealander (and first male new zealander) to win a medal at a winter olympics. at age 16 years 91 days, porteous subsequently became new zealand's youngest olympic games medallist, breaking the previous record of 16 years and 353 days set by zoi sadowski-synnott earlier the same day, who had in turn broke the record of 17 years 100 days set by danyon loader at the 1992 summer olympics.