Warren competed in the Junior men where there was a strong line up of eight competitors. He didn't place this time, but was in the top four.
Five weeks ago Dixon also won the NABBA overall title in Hastings.
"This now qualifies me for the Natural Olympia in Los Vegas in November where I will defend my Natural Miss Olympia title, Dixon said.
"A big thanks must go to Pat Mcnamara from City Gym Wanganui for all his guidance and patience, my husband Calvin, my children and my two new training partners, Tim Warren and Krista Adams."
Dixon and McNamara have been together for a decade now and she has won numerous high profile titles at competitions in New Zealand, Australia, the United States and at the worlds in Dubai just last year.
"Bodybuilding is not a high profile sport in New Zealand and most people don't realise the dedication and hard work that goes into winning the titles Jan has," McNamara said.
"We prefer the natural competitions where there is no drugs. Jan is peaking at the right time for the Natural Olympia show in Los Vegas, but we will go to Wellington and then the New Zealand Nationals in Napier to put the final polish on. The nationals are not natural competitions, but we've beaten these guys before," he said.