Iran's interior minister says moderate candidate Hasan Rowhani has won the presidential vote.
Mostafa Mohammad Najjar said at a press conference in Tehran that Rowhani obtained more than 50% of more than 36 million votes cast in Friday's election.
Rowhani was the lone moderate candidate in the race supported by reformists that once appeared solidly in the hands of Tehran's ruling clerics.
Rowhani's conservative and hard-line opponents were far behind the moderate Rowhani who has vowed to follow a policy of detente and interaction with the outside world.
The powerful showing by the former nuclear negotiator allowed him to avoid a two-person run-off and demonstrated the strength of opposition sentiment even in a system that is set against it.
The ruling clerics barred from the race reform candidates seen as too prominent, allowing a list of hopefuls who were mainly staunch loyalists of the supreme leader. But the opposition settled on Mr Rowhani as the least objectionable of the bunch, making him the de facto reform candidate.
While Iran's presidential elections offer a window into the political pecking orders and security grip inside the country - particularly since the chaos from a disputed outcome in 2009 - they lack the drama of truly high stakes as the country's ruling clerics and their military guardians remain the ultimate powers.
Security forces also are in firm control after waves of arrests and relentless pressures since the last presidential election in 2009, which unleashed massive protests over claims the outcome was rigged to keep the combative Mahmoud Ahmadinejad in power for a second and final term. He is barred from seeking a third consecutive run. However the last-moment surge around Mr Rowhani injected some excitement in the race.
Rowhani won with 50.7% of the more than 36 million votes cast, the Interior Ministry reported, well ahead of Tehran mayor Mohammad Bagher Qalibaf with about 16.5%. Hard-line nuclear negotiator Saeed Jalili came in third with 11.3% followed by conservative Mohsen Rezaei with 10.6%.
Minister Mostafa Mohammad Najjar said the turnout was 72.7%, suggesting that liberals and others abandoned a planned boycott as the election was transformed into a showdown across the Islamic Republic's political divide. Iran has more than 50 million eligible voters.