Iraq's Sairoon coalition, led by opposition leader Muqtada al-Sadr, came in first in Saturday's parliamentary polls, while the pro-government Al-Fatih coalition, led by Hadi al-Amiri, came in second, according to unofficial results. But in a conciliatory statement Monday, Mr Al Abadi called on citizens to respect the results and put the well-being of the country first.
Analysts say he also benefited from his ability to command a fiercely loyal base in an election that saw historically low turnout.
Mr. Abadi, a rare ally of both the USA and Iran, is mainly concerned with fending off Shia groups other than Mr. Sadr's alliance, which are seeking to pull the country closer to Tehran.
To enable this, his movement effectively exploited the network set up by his father, Grand Ayatollah Mohammad Sadeq al-Sadr, who was assassinated in 1999 during the period of Saddam Hussein's dictatorship.
Meanwhile a new diplomatic meeting on Syria opened on Monday morning in Astana, the capital of Kazakhstan, with the participation of the main regional powers and actors involved in the conflict, broadcaster Al Arabiya reports.
The winners not only scramble the pyramid of power in Iraq but also raise the possibility of a government with radically new priorities.
"This gave him more supporters than he had before", Mayali added.
Whoever wins the election will have to contend with the fallout from U.S. President Donald Trump's decision to quit the Iran nuclear deal, a move Iraqis fear could turn their country into a theatre of conflict between Washington and Tehran.
He was viewed as a frontrunner before the election.
Abadi - who came to power as IS swept across Iraq in 2014 - has been a consensus figure who balanced off the USA and Iran. But the defeat of Islamic State and Abadi's campaign to eradicate Iraq's rampant corruption improved his standing.
Abadi, preferred by the US and credited for overseeing the crucial battle against Daesh as well as curtailing Kurdish independence ambitions, spearheads the Victory (Nasr) list. However, the Kurds will still have a key role to play in coalition forming and various Arab alliances will try to entice Kurdish support.
Sadr is one of the few Shia leaders to keep a distance from Iran, and instead shares Saudi interest in countering Iranian influence in Iraq. Former prime minister Nuri al-Maliki, a close ally of Iran like Amiri, came in fourth with around 25 seats.
"Iraq is rich, the country doesn't need Iran, it can stand on its feet and be prosperous it just need good management", said Mohammed Sadeq, a trader in the city of Hilla who voted for Sadr's list.