A polling station survey published by the TV channel Unitel shows that Arce gets 52.4 percent of the votes already in the first round.
Former president and center-right candidate Carlos Mesa is in second place with 31.5 percent.
In order for the election to be decided in the first round, it is required that a candidate receives at least 40 percent of the votes and that it is at least 10 percentage points to the second, criteria that Arce thus appears to have fulfilled with flying colors.
"Without hatred"
"I am very grateful for the support and trust of the Bolivian people.
We have restored democracy and we will restore the stability and calm of society, ”Arce tweets.
He struck a more humble tone in statements to journalists at midnight local time.
"We will resume the process of change without hatred," Arce said, adding:
- We will draw our lessons and come to terms with the mistakes we have made before.
Morales heir
The election in Bolivia takes place in the light of the political crisis that was triggered in November last year when the then left-wing leader Evo Morales was forced out of power after a controversial election that led to violent protests.
Morales, who is in exile in Argentina, belongs to the same party as Arce: Mas, who ruled the country for almost 14 years.
The pandemic and the economic crisis in its wake have further complicated the situation.
Since Morale's departure, Bolivia has been led by a transitional government led by conservative Jeanine Áñez.
She states that Arce seems to have won the election and congratulates him on that.
Re-election has been postponed twice due to the risk of spreading the infection.