The 26-year-old won the 130kg weight division in Canberra last month to claim the title.
Humberston said it was a tough competition against some former Commonwealth Games representatives and some of the best competitors from the former Soviet Union and Middle East.
He said the Australian Institute of Sport was a great venue for the national championships.
The 2018 Commonwealth Games hopeful travels from his home in Baldivis to the Subiaco PCYC three nights a week for training.
Humberston said he complemented that training with boxing and fitness workouts several times a week.
Tigers Greco-Roman wrestling head coach Adrian Tesanovic said Humberston’s gold medal at the national championships was the result of hard work and commitment to his sport.
‘He is very talented and we expect him to achieve even more,’ Tesanovic said.