JAKARTA - Incumbent president Joko Widodo and his running mate Ma'ruf Amin are ahead in several quick counts that are being carried out by different pollsters.
Quick counts from five pollsters give the incumbent between 54.4 per cent and 55.7 per cent of the votes, with around 38 per cent of votes counted.
The same counts give Mr Prabowo between 45.6 per cent and 43.9 per cent of the votes.
Based on internal survey from the Jokowi-Ma'ruf team, the ticket will gain victory with a score of 57 to 58 per cent, Mr Hasto Kristiyanto, the secretary-general of the Indonesian Democratic Party of Struggle, told reporters in a Kompas TV broadcast.
As voting for Indonesia’s biggest round of elections got off to a smooth start, both presidential hopefuls were upbeat about their chances at the polls.
President Joko, who is seeking a second term in office, showed up at his polling station at the State Administration building in Central Jakarta on Wednesday, while his 76-year-old running mate Ma'ruf cast his vote in North Jakarta.
When asked about his chances, Mr Joko, who was at his polling station about two hours before the polls are set to close, said he remained optimistic, adding: "The way we work is we are always optimistic."
And to a question on his expected winning margin, the President, in his signature folksy drawl, told reporters: "Later lah, be patient, we will see later. It's only been a few hours, we will see later."
Mr Joko, who goes by the popular moniker Jokowi, said his plan after voting was to "makan (eat)... with Ibu Jokowi", referring to his wife.
His opponents, presidential hopeful Prabowo Subianto, 67, and his running mate Sandiaga Uno, 49, showed up at their respective polling stations in Hambalang, West Java, and South Jakarta bright and early. They later posed gamely for the media with two ink-stained fingers - their ballot number is 02 - extended.
Mr Prabowo was also feeling good about his chances. "I'm feeling optimistic," he told a reporter, according to The Jakarta Post. "We estimate (we will win) with 63 per cent."
Election officials have begun a manual count of votes casts after the polls closed at 1pm local time on Wednesday.
Official results for the elections will only be announced about a week later, but unofficial "quick count" results are expected to be released in a few hours' time.
Quick counts conducted by private polling and survey agencies, which look at a sample of ballots after polling closes to estimate the overall vote, have largely proven to be accurate in past elections.
There have been worries about possible unrest over the results of the tight presidential race that has divided a nation. Mr Prabowo - who challenged the results of the 2014 presidential elections, in which he lost to Mr Joko by a margin of about six percentage points - has urged his supporters to act peacefully, but added on Wednesday that any chaos that ensues would be “out of his hands”.
"If the election is held honestly, there should be no problem," said Mr Prabowo, whose team has raised doubts over voter rolls, claiming that 17.5 million names on the list are problematic. "But I don't have power over (any potential conflicts)."
Mr Sandiaga, speaking to reporters at his polling station, said that on the campaign trail these past months, he had seen how truly rich in resources Indonesia is.
"Our tremendous human resources are sometimes forgotten," he said, adding that the polls were a referendum on the economy.
"I'm happy and thankful that this election has been about the economy, on issues such as job opportunities - especially for millennials - and the prices of staples for housewives. We focus on the issue of the economy, which unites us, instead of other issues that have the potential to tear society apart," Mr Sandiaga said.
Voting in Indonesia's biggest round of elections yet got off to a smooth start on Wednesday, with minimal delays at the more than 800,000 polling stations around the country.
This year, the presidential and legislative elections are taking place on the same day for the first time in the country's history, with more than 192 million Indonesians eligible to vote for their president and local representatives.
Home Affairs Minister Tjahjo Kumolo said the process has gone smoothly so far.
"Hopefully ,we will not see any obstacles later today. We would be barred from voting only if a natural disaster strikes. Otherwise, everything should go smoothly," he told reporters after casting his vote at a polling station in South Jakarta this morning.
"The government appreciates the voters who have exercised their rights peacefully and orderly. We also thank the security officers who have so far helped to keep the situation conducive to voting."
TURNOUT A CONCERN
Voter turnout has been a major concern this election. Abstention rates are expected to hit 30 per cent, prompting the country to go all out in efforts to get people to the polls - from rallying businesses to roll out discounts and freebies for voters who flash their ink-stained fingers, to engaging influencers to send the message that "voting is cool".
Key public figures have also repeatedly called on Indonesians to exercise their right to vote.
West Java governor Ridwan Kamil urged those in his province to make their voices heard at the ballot box.
"Your ignorance will later become your regret. By voting, we ensure that our quality of life in the next five years will be what we hope for," he told reporters.
Many polling stations drew excited early birds.
Retired teacher Sonya Inna, 70, who arrived before polls opened, said: "I came earlier than usual because I'm enthusiastic."
She had been worried about the complex voting process - which involves five ballot papers for the president and four other officials at the local and regional level - but the entire process took her just three minutes in the end, helped along by information about the voting process she had received in WhatsApp groups.
Still, even as lines of enthusiastic voters formed up early, a few polling stations were dogged by delays.
Part-time used car dealer Arman said voting was delayed for an hour at his polling station in North Sukabumi, Jakarta, because official witnesses for the polls were late.
Voting at a polling station in Selayang district in the North Sumatran capital of Medan started over an hour late, as officials were slow to set up the station.
"I'm disappointed with this delay," said taxi driver Umbara, who showed up at 6.30am raring to vote and go on with his day. "I had wanted to vote and quickly start my shift."
EYES ON PRESIDENTIAL POLLS
The presidential election was the focus of many voters, with the legislative candidates taking a back seat.
Batamindo Industrial Park employee Giovani Boru Sembiring, 24, said: "I'm very excited to be voting for our president and vice-president, but I have not thought much about the legislative candidates for Parliament and other local councils because I don't know any of them."
And voters were vocal about their picks.
Ms Sandi, 33, a resident from West Jakarta, said: "Of course I will choose Jokowi. We have seen what he has done these past four and a half years. He should be president again.
"Last time, I was in (Kuala Lumpur) for the election so I couldn't vote. I'm very excited to do so this time."
Before Mr Antoni, who goes by one name, headed off to vote in Central Jakarta, he hung around the polling station Mr Sandiaga would be voting at, looking for a chance to get a selfie with him.
The bicycle salesman, who voted for Mr Prabowo - a retired army general - in the 2014 presidential polls, said: "I still think Mr Prabowo has the temperament needed to lead Indonesia. He is firm, a military man. And he has the better choice of running mate this time round. Mr Sandi is very energetic and charismatic, and with a strong business background.
"Prabo-Sandi is better than Jokowi-Ma'ruf."