They include tens of thousands who packed the venue of last year's Asian Games as early as 4am local time to join the candidates for the salat subuh Muslim dawn prayers.
By the time Mr Prabowo took to the stage at around 8am, the sea of supporters mostly dressed in white were already out in force.
Most were on the football field, over the Olympic-sized running track, and in the stands, but there were also many spilling out to the parameters of the 77,193-seater stadium.
Mr Prabowo said his rally organisers estimates that there could be a million attending what they believe is the largest political rally in Indonesia's history.
Still, an official count for such large-scale, un-ticketed events, are usually hard to establish.
The former general did not give a rousing speech as one would come to expect from an event of such scale.
Instead he addressed supporters in an almost laddish tone, which the crowd seem to respond well to, cheering as he made jibes at the incumbent President Joko Widodo's handling of the country's flagging economy, as well as his smart-card initiatives.
"People want jobs, not cards," said Mr Prabowo.
He also repeated the importance of fighting graft, adding that corruption in Indonesia is like a disease, alluding that it was akin to "stage-four" cancer.
"Corruption has stolen our economic resources that would have otherwise benefited the people," he said. "Look, some of our people don't even have access to clean water, now, what kind of a republic can't even provide clean water for its people?"
Mr Prabowo also criticised the high mark-ups in the cost of infrastructure projects under the current administration.
This is the second time Mr Prabowo is running against Mr Joko for the presidency, after the incumbent defeated him in at the 2014 race by 53.15 per cent to Mr Prabowo's 46.85 per cent of the votes.
The Gerindra Party leader also contested but lost at the 2004 polls as former president Megawait Soekarnoputri's running-mate.
Mr Prabowo still trails behind Mr Joko in most electability surveys.
However, with 10 days to the polls, many observers are expecting a tight finish.