Polls opened Wednesday in Jakarta's election run-off with the Christian governor fighting for his job despite standing trial for blasphemy, in a vote that has stoked religious tensions in Muslim-majority Indonesia.
Basuki Tjahaja Purnama is facing a Muslim challenger, heavyweight ex-minister Anies Baswedan, in a neck-and-neck race to lead the teeming capital of over 10 million people.
Purnama, the city's first non-Muslim governor for half a century and its first ethnic Chinese leader, won in the first round in February but not by a big enough margin to avoid a run-off.
The race was already significant as politicians see the job as a stepping stone to the presidency at 2019 polls, but the stakes were raised dramatically by a controversy over claims that Purnama insulted the Koran.
The allegations drew hundreds of thousands of conservative Muslims onto the streets of Jakarta in major protests last year, and led to Purnama -- known by his nickname Ahok -- being put on trial for blasphemy in a case critics see as politically motivated.
Purnama, 50, has seen a once-unassailable poll lead shrink, and the vote has become a test of whether the traditional, tolerant brand of Islam in the world's most populous Muslim-majority country is under threat from the rising influence of hardliners.
"This is Indonesian pluralist Islam versus a new type of political Islam that is pushed by hardline Islamists," Tobias Basuki, a Jakarta-based political analyst at think-tank the Centre for Strategic and International Studies, told AFP.
Polls opened at 7:00 am (0000 GMT) and will close at 1:00 pm, with over 7.2 million people registered to vote. Over 60,000 security forces have been deployed.
Early vote tallies from private pollsters due to be released in the afternoon should give an indication of how the candidates have performed although official results will not be announced until early May.
Despite Purnama's first-round victory, former education minister Baswedan, 47, was initially seen as the favourite in the run-off because the votes from a third, Muslim candidate who was knocked out were expected to go to him.
But with tension over the governor's alleged blasphemy subsiding in recent weeks, Purnama has regained momentum. Recent polls show the two candidates almost neck and neck, although most put Baswedan ahead by a wafer-thin margin.
Purnama's troubles began in September when he lightheartedly said in a speech that his rivals were tricking people into voting against him using a Koranic verse, which some interpret as meaning Muslims should only choose Muslim leaders.
If Purnama -- who won popularity for his determined efforts to clean up Jakarta -- does win the vote and is then convicted of blasphemy, he would not automatically be barred from holding office and could avoid jail for a long time by filing successive appeals.