The first round was a tight affair and that was reflected in the judges' 3-3 scoring.
Both fighters came forward more in the second and it was Araujo who was taking the upper hand by landing with some powerful shots.
However, it was Ochigava who got her nose in front at 8-6 after two rounds.
That did not deter the Brazilian, who got through with a couple of snapping left hooks that threw her opponent off balance.
Araujo began to look comfortable in the ring and she was the one who was dictating the flow. Two more thudding blows cannoned off the Russian's head guard.
Despite being seemingly in control, Araujo fell further behind and trailed by four points heading into the final round.
Ochigava chose to fight on the back foot in the final round as she sought to preserve her advantage. It worked, and she went on to claim a 17-11 decision.