Hours after polling began to end on Sunday, Bolivians waited anxiously for results in an election that many hope can restore stability after a voided ballot last year plunged the nation into crisis and ended the long rule of Evo Morales.
After governing Bolivia for nearly 14 years, Morales eventually quit in the wake of the fraught 2019 election, which sparked bloody protests.
Voting during the day appeared to go smoothly, but five hours after polls began to close, Bolivians were still guessing about where the election was headed.
The official count had tallied just over 2% of votes by around 11pm (0300 GMT) and expected exit polls had failed to materialize.
The election is likely to set Bolivia's political course beyond Morales, the socialist indigenous leader whose shadow still looms large over the country, despite him living in exile in Argentina since the fraught vote last year.
This is a fundamental moment in the history of our country, one of the main candidates, centrist former president Carlos Mesa, said as he cast his vote in La Paz on Sunday.
In pre-election polls Mesa had been in second place behind Luis Arce from Morales' socialist party, though polls then had suggested a second round run-off would be needed.
Jose Luis Galvez, who heads pollster Ciesmori, said on local TV station Unitel that more Bolivians than usual had declined to disclose their vote, making their exit poll unreliable. He added getting a quick-count poll out – which involves tallying votes at the voting stations themselves -- would take time.
Bolivia's conservative interim president Jeanine Áñez implored citizens to be patient.
We should all be patient to wait for the election results without engaging in any type of violence, said Áñez, who took over in a power vacuum last year after Morales resigned. I assure you that we will have credible results.
Arce, who earlier this week suggested the only way his rivals could win was through fraud, also moved to calm rhetoric that has led some to worry about a return of violence that rocked the country last year and left scores dead.
Let's hope that today and the following days pass peacefully. In the MAS we are committed to a democratic solution, we do not take power by arms, we do it through a democratic way, he told reporters after voting.
The vote, carried out in person despite the coronavirus pandemic, will be a test of the left's clout in Latin America. Morales was an iconic and long-lasting figure in a wave of leftist presidents in the region over the last two decades.
The vote is set to be the most important since Bolivia returned to democracy in 1982, said Carlos Valverde, a political analyst.
Bolivia erupted in violence late last year when Morales sought a fourth term in a disputed election that has since been annulled. The violence cost at least 30 lives, sparked food shortages and forced Morales to resign.
On Sunday, residents of La Paz, a city starkly divided by class and race, were voting peacefully but faced long lines meant to avoid overcrowding inside voting locations.
Many said they worried the election result could lead to more violence, especially if Arce's vote count falls short.