Cox finished seventh overall after going down to Kazakhstan’s Yulia Galysheva in their round of eight heat.
Galysheva went on to win silver.
“Yulia is an excellent skier, a fast skier and I tried to put up a good fight but she was definitely a clear winner in that one,” Cox said.
“Dual Moguls is so much fun but anything can happen. There’s generally a lot of upsets and I went in there trying to put down run after run," she said.
Earlier in the day it was an all Aussie affair in the women's event when Cox went head to head against her young compatriot Jakara Anthony in the round of 16. Cox earned her quarter final berth with a 21 - 14 victory against 18-year-old Anthony who is competing at her first World Championships.
Anthony went on to finish 16 from a field of 31 starters. Fellow Aussie Madi Himbury was eliminated in the round of 32 and finished 24th. France's Perrine Lafont won gold.
In the men's event Matt Graham made it to the round of 16 where he drew American skier Thomas Rowley as his opponent. The closely contested heat was awarded to Rowley which saw Graham finish 10th in the overall standings.
Brodie Summers and James Matheson could not advance from the round of 32, finishing 18th and 28th respectively.
The men's final was not without drama with both finalists crashing before the finish. Ikuma Horishima of Japan and Wilson Bradley of the United States pushed the limits and scrambled to the line in an effort to win gold with victory ultimately being awarded to Horishima.
The 2017 FIS Freestyle Ski and Snowboard World Championships brings to an end the 2016/17 Mogul Skiing season.