MANILA, May 9 (Reuters) - Ferdinand Marcos Jr clinched a stunning runaway victory in the Philippines' presidential election on Monday in the first win by a majority since a 1986 revolution that toppled his late father's two-decade dictatorship.

An unofficial tally showed Marcos, popularly known as "Bongbong", had surpassed the 27.5 million votes needed for a majority, setting the stage for a once unthinkable return to rule of the Marcos family, 36 years after its humiliating retreat into exile during a "people power" uprising.

"I hope you won't get tired of trusting us," Marcos told supporters in remarks streamed on Facebook, a platform at the core of his political strategy.

"We have plenty of things to do," he said, adding "an endeavour as large as this does not involve one person."

Marcos Jr had 29.9 million votes, double that of Leni Robredo, the vice president, with 93.8% of the eligible ballots counted, according to the unofficial Commission on Elections (COMELEC) tally. Turnout was about 80%.

An official result is expected around the end of the month.

Despite its fall from grace, the Marcos family returned from exile in the 1990s and has remained a powerful force in Philippine politics, retaining its influence with vast wealth and far-reaching connections.

Marcos Jr has served as a governor, congressman and senator, his sister, Imee, is currently a senator and mother Imelda, the influential power-broker and widow of the late dictator, served four terms in congress. Marcos Jr's son Ferdinand Alexander was poised to win a seat in congress on Monday.