Initial exit polls gave Yudhoyono, Megawati's one-time chief security minister, 62 percent of the votes, while Megawati stood at 38 per cent.
Turnout in this runoff, which ends a poll season which began with parliamentary elections in April, was pegged at 80 percent.
Though Yudhoyono had won the first round of the election on July 5, he failed to win an outright majority over the four other candidates, including Megawati, which forced the run-off.
The
Though the tally is being regularly aired by the election commission, the final results will be formally declared on October 5, 15 days before the new President takes charge October 20.
Yudhoyono's popularity is probably due to his tough stand on terrorism and corruption, which also endears him to the west, say analysts.