State MLA for Willagee Peter Tinley is WA Labor's new State president.
Mr Tinley, a former SAS major, prevailed in a popular secret ballot of Labor members over the Maritime Union's Adrian Evans.
Mr Tinley polled 641 votes to Mr Evans' 579 in a result that will surprise some people inside the party.
Even Mr Tinley's backers on the Right expected the numbers from the MUA and the Left to swing in behind Mr Evans, who ran unsuccessfully at the last Federal election against Liberal Ken Wyatt in Hasluck.
Mr Tinley will preside over Labor's State conference at the weekend.
"I'm very proud to be given the trust of my party to help move Labor towards electoral victory in the future," Mr Tinley said.