Queenstown-based local favourite Gotlieb landed a back-flip somersault off the slopestyle course's massive final kicker jump as she tried in vain to claw past Anderson's top-scoring first run of 79.2 points.
The trick pushed Gotlieb's final score to 74.56 points, but it was not enough to trump Anderson's effort.
Swiss snowboarder Christian Haller claimed his first major international snowboarding title when he outscored Norwegian pair Gjermund Braaten and Mikkel Bang to win the men's slopestyle by 0.24 points.
Haller (20) scored 80.84 and said he wanted to make sure his runs counted in the challenging conditions.
"I didn't think about it too much. I just took it easy and made sure I landed a clean run, rather than trying to do anything too technical," he said.
Anderson (19) has owned the NZ Burton Open slopestyle title since she first triumphed at the event in 2008, a year in which she dominated and won the halfpipe title as well.
"The first run was pretty hard to see and scary.
"It wasn't my most technical run, but I landed everything. I wanted to step it up on the second, but the weather only got worse and it got harder and harder to ride."
Swirling low cloud, mist and poor visibility forced organisers to cancel the morning's scheduled semifinals, and all of the qualified riders instead progressed to a "super-final" in which competitors' best score of two runs was counted.
The re-schedule meant the slopestyle's 37 male riders and 19 female competitors took to the cloud-cloaked course in an extended finals session.
Jake Koia, of Arrowtown, was the best-performed New Zealand male, in 28th place with a score of 51.48 points, followed by James Hamilton in 35th with 44.16 points.
The action shifts today to the halfpipe finals, in which Wanaka siblings Mitchell and Kendall Brown will carry local hopes in their respective men and women's competitions.
