About 70 athletes braved blizzard conditions on the Pisa Range near Wanaka to race each other side-by-side down a parallel giant slalom course.
A determined Edwin Coratti (19), of Italy, held off the competition's fastest male qualifier, Lukas Mathies (19), of Austria, by mere hundredths of a second to clinch the title.
The driving snow, wind, and near-zero visibility did not stop Coratti from enjoying his win.
"It was a great day. Lukas was my closest rival and it was very hard racing against him but I did it," he said.
Annamari Chundak (20) of Ukraine, was untouchable in the females' racing, as she posted the fastest qualification time on her way to winning the gold medal.
Chundak, who is ranked 36th in the world, maintained her early lead as competitors tried in vain to beat her time.
Competition was tough, although she maintained the "horrible weather" had not affected her racing.
"I believed in myself and now I am so happy to be world champion. We train in all different conditions so it didn't affect me so much," she said.
Julie Zogg, of Switzerland, secured silver as Ina Meschik, of Austria, held on for bronze.
The snowboard alpine events continue today with the parallel slalom at Snow Park due to start at 9am, and finals scheduled for 12 noon.
