Hall, who was raised in Outram and is now based in Wanaka, said the win fulfilled a 15 year dream.
He won the race despite falling halfway through his second run and afterwards said: "I can't explain it, I'm wordless. It's been a 15 year dream to come here and win a gold medal".
His gold medal in Vancouver was New Zealand's first medal at the Winter Paralympics since 2002.
Hall, 22, who has spina bifida, had to beat a combined time of one minute 45.97 seconds set by German Gerd Schonfelder, and got there with around half a second to spare.
Talking to Sky Sports after his victory, Hall joked that his fall was on purpose and said he "just got back on the horse" and tried not to think about how it would affect his medal prospects.
"To cross the finish line and see my name and country on the top of the scoreboard was unbelievable," he said Hall went to Vancouver hoping to get a gold medal and said "you don't just come here to get second or third".
His grandfather travelled from Dunedin and his mother, who was also in the crowd, said she had stopped breathing halfway through the race. Defending a lead of more than two seconds after the first run, Hall skied well at the start of his second run, but looked to have lost all chance when he fell.
But he scrambled back up to finish the course 0.57sec ahead of Schonfelder with a two-run time of 1min 45.40sec. He looked distraught at the finish, until he saw his name flash up in the gold medal position.
Schonfelder, who had powered down his second run to move into the lead, took the silver medal ahead of Australian Cameron Rahles-Rahbula, who was second after the first round.
Hall led after the first round with a time of 50.95sec, 2.13sec quicker than Rahles-Rahbula.
After the first run Hall said he was happy with his time but could not afford to get too excited.
"It's a two-run race. It's not just one race, so after the first run it doesn't mean anything," he said.
In the end his two second buffer was enough to stave off his rivals.
Hall is one of only two New Zealanders competing at the Games. Peter Williams is competing in the slalom and the giant slalom.
New Zealand last won a Winter Paralympics medal eight years ago in Salt Lake City, where Rachel Battersby won three golds, and Steve Bayley a gold and two bronze.
Hall was ranked second coming into the Games, after a good 12 months leading up to the event. He was the New Zealand Snow Sports Athlete of the Year 2008-2009 and contested the 2006 Winter Paralympic Games in Italy.
Hall still has three events left at the Games. He will compete in the giant slalom on Thursday (NZ time), the super G on Sunday and the super combined on Monday.
