Mrs Mandrakamu polled 722 votes to beat all 27 other contestants to become the first female LLG President in the province.
She led from when counting started on Sunday until her declaration as winner.
She was the only woman candidate among all the men candidates in the race for that seat.
She's the first female elected as president of one the 12 LLGs.
Besides the former broadcaster, Manus also saw two other female ward councillors elected in LLGs of Los Negros and Rapatona.
Counting is still continuing in some other LLGs.