Ex-general Susilo Bambang Yudhoyono has kept his lead over closest challenger Megawati Sukarnoputri, with about two-thirds of the vote tallied from Indonesia's first direct presidential election.
Current president Megawati remained ahead of third-placed Wiranto, a former armed forces chief who is standing for the largest party Golkar.
Megawati, who has come back strongly after being written off by polls and pundits earlier this year, seemed set to battle her former security minister Yudhoyono in a runoff on September 20 between the top two vote-getters.
Both camps were lobbying for the backing of Golkar, the political vehicle of former dictator Suharto, or of other parties before the runoff.
Golkar deputy chairman Bomer Pasaribu, quoted by Koran Tempo newspaper, said Yudhoyono or Megawati must form a coalition with his party if they want to win the runoff.
Megawati's running-mate Hasyim Muzadi, quoted by Media Indonesia, said he would soon begin lobbying for backing from the National Awakening Party (PKB), which finished third in the April parliamentary election in terms of vote numbers.
But PKB deputy chairman Mahfud Mahmuddin was quoted by the same newspaper as saying rationally it should form a coalition with Yudhoyono.
Whoever wins the runoff will need to build a coalition of some sort to push legislation through parliament. Even Golkar will have only 128 seats in the new 550-member house.
But some commentators said the current focus on coalition-building is premature and even pointless, since an increasingly independent-minded electorate voted for personality rather than on party lines in Monday's election.
"Coalition? Who needs one?" the Jakarta Post headlined its editorial. The present horse-trading (or cow-trading, to use the Indonesian expression) "shows that our political leaders have not reached the same rationality and maturity that voters showed on Monday," it said.
The Post said the right time to build coalitions is after the runoff and dismissed the current moves "as silly little games." Turnout in the election – another milestone in Indonesia's democratisation after the fall of army-backed strongman Suharto in 1998 – was estimated at 82 percent or about 125-126 million.
A candidate would need to get at least 50 percent of the vote to avoid a runoff. The winner of the runoff was anyone's guess. Commentator Wimar Witoelar, in a Post article, said Yudhoyono is still the favourite but faces an uphill campaign.
"Susilo is basically a decent person and presents a clean image," wrote Witoelar, a former spokesman for President Abdurrahman Wahid. "However, more people now realise he is ex-military, a top general in the Suharto government." He said Megawati still does not inspire thinking people but "at least she does not evoke fear of hardline policies the way her military rivals give the public cold feet."