Socialist Michelle Bachelet handily won a first round of Chile's presidential race Sunday, but despite a crushing margin of victory still faces a runoff vote against conservative rival Evelyn Matthei.
With 99 percent of the vote counted, Bachelet had nearly 47 percent against 25 percent for Matthei, Chile's Electoral Board said.
Bachelet failed to reach the 50 percent needed to avoid a runoff, so a second round of balloting is set for December 15.
"We knew that it would be tough to win on the first round, we worked really hard, and we almost did it," Bachelet told supporters late Sunday.
"We did win tonight, and we are going to work hard to win comfortably in December."
Bachelet, Chile's first woman president in 2006-2010, is eyeing a second term as leader of the South American nation with the highest per capita income.
Matthei was relieved to have a second chance to reach out to voters. "I am really pleased. We will have a runoff," she told reporters.
Both women are seeking to succeed conservative billionaire President Sebastian Pinera, who is barred from a consecutive re-election.
Trailing Matthei and Bachelet were independent economist Franco Parisi and Socialist Franco-Chilean filmmaker Marco Enriquez-Ominami with about 10 percent each. The remainder of the vote was divided among five minor candidates.
A pediatrician by training, Bachelet, 62, wants to overhaul the country's political and economic system, a legacy of Augusto Pinochet's 1973-1990 military dictatorship.
She has pledged to bring a "new cycle" of reforms to reverse the country's wide income gap.
Bachelet wants to legalize abortion and raise business taxes to offer free university, answering the demands of a powerful student movement that led a series of massive protests since 2011.
Chile has the highest GDP per capita in Latin America -- $22,362 based on purchasing power parity -- but half of the nation's 17 million people make less than $500 per month.
The daughter of an air force general and a separated mother of three, Bachelet is supported by a "New Majority" alliance of socialists, Christian Democrats and communists.
Matthei, 60, is a former labor minister under Pinera and former legislator for the ultraconservative Independent Democratic Union (UDI). She was the first woman presidential hopeful chosen by Chile's right.
Matthei's father was also an air force general, and as children she and Bachelet played together on a military base in Chile's parched north.
However Bachelet's father died after being tortured for supporting slain leftist president Salvador Allende, while Matthei's father supported the dictatorship that came to power in a 1973 coup.
Matthei has called for a continuation of the legacy of the unpopular Pinera, claiming that a back-to-Bachelet era would be a step backwards.
Pinera took office when Bachelet's first term ended in 2010. She went on to head the United Nations office that promotes gender equality.
Preliminary results also show that Bachelet's coalition will have a simple majority in both chambers of congress.
This will allow her to carry out proposed reforms of the tax code and education system, but is not sizeable enough to overhaul the constitution, a holdover from the Pinochet era.
One of the new legislators swept into office is Camila Vallejo, 26, the charismatic young leader who helped organize the massive student protests that rocked the Pinera presidency.
Balloting generally went smoothly, though a group of protesting students occupied Bachelet's campaign headquarters calling for election reform. There were no immediate reports of damage or injury.
More than 13 million people were registered to vote.
For the first time since democracy was restored in 1990, voting was no longer compulsory.
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