The breakaway ethnic Armenian enclave of Nagorno-Karabakh has elected a separatist former security chief as president, election officials say.
Mr Sahakyan wants international recognition for Nagorno-Karabakh
Bako Sahakyan secured 85% of the vote in a landslide victory.
Nagorno Karabakh is part of Azerbaijan, which has dismissed the vote. Thousands died when Azerbaijan and Armenia fought over the area in the 1990s.
Mr Sahakyan has said he wants the poll to help Nagorno-Karabakh secure broader approval for its claim to independence.
No country currently recognises the enclave's claim.
Turnout in the election was high, the territory's election commission said, with 77% of 91,000 registered voters having cast their ballots.
Thursday's presidential election was the fourth held in the territory since Azerbaijan lost control of it in 1995.
Armenia and Azerbaijan fought a bitter war over Nagorno Karabakh
Mr Sahakyan's main rival, Masis Mailian, got 12% of the vote, election officials said.
Both candidates had expressed their support for the territory's claim to independence.
BBC correspondent Matthew Collin says the election to the presidency of a former security chief shows memories of war remain fresh in the region.
The outgoing leader of Nagorno-Karabakh, Arkady Gukasyan, had said the territory had a stronger claim to independence than the Serb province of Kosovo.
But the UN, which is considering a plan that offers Kosovo "supervised independence", has rejected any similar settlement for Nagorno-Karabakh.
Azerbaijan says the separatist Armenian authorities came to power in Nagorno-Karabakh as a result of ethnic cleansing and that the enclave must not be allowed to break away.
Armenia insists the region has the right to choose its own destiny.
Years of talks between Azerbaijan and Armenia have failed to deliver a peace deal.