The 25-year-old, whose original plan was to “compete in just the time trials and maybe do one round of heats,” finished third in Sunday’s qualification runs before progressing through to the Small Final.
Having recently received medical clearance to compete in PyeongChang 2018, Brockhoff said it was “good to be doing the sport I love again.”
“It felt really good to be back, laid down a solid time trial even with a few mistakes than in training,” she said.
“I wanted to do a few heats to get back into the swing of things and got into the Small Final. Took a really hard landing during the first heat which flared up my knee a bit but wanted to push through the pain.
“I know I didn’t have an excuse to not be in the Big Final by looking at the way I was riding but I’m really happy regardless with where I’m at.
“I haven’t raced in 11 months so I really needed to get this under my belt. It gave me a lot more confidence with my riding but I do have a lot of hard work to do.”
In the men’s event, Brockhoff’s fellow Olympic teammates Jarryd Hughes and Alex ‘Chumpy’ Pullin also managed to secure top ten results.
Hughes, who will be competing in his second Winter Games, finished the second day of competition in six place and said that he “couldn’t be more excited” to be heading to Korea.
“I was able to carry some speed through heats and then got to work on my starts which was huge,” he said.
“I definitely improved throughout the day and in the Small Final got to practice some passing and get some battles happening which is good heading into Korea.
“I’m feeling great and have really benefited from a lot of help from dual Olympic Champion Seth Westcott (USA) so that’s been a huge help both for my performance and my confidence.”
Pullin, who is set to make his third Olympic appearance in PyeongChang, finished ninth and currently sits in second place on the World Cup standings behind long-time rival Pierre Vaultier (France).
Improving on their results from the opening day of racing, Cam Bolton finished 14th while Olympic debutant Adam Lambert ranked 19th.
Fellow Aussies Matthew Thomas and Josh Miller were unable to qualify for the eighth finals, finishing 38th and 40th respectively.
The Australian men will take to the snowboard cross track on Day 6 (February 15) of the PyeongChang 2018 Games at the Bokwang Phoenix Park while Brockhoff, the Australian team’s only female boardercross rider, will compete on Day 7.