When just over 90 percent of the votes had been counted, Paz had voter support of 32.8 percent. He thus placed himself before the right-wing candidate and former president Jorge "Tuto" Quiroga, who had received 26.4 percent of the votes at the same time.
To win the presidential election, 50 percent of the votes are required, or 40 percent with a ten percentage point margin to the second place. This means that the candidates will now be pitted against each other in a second round of voting on October 19.
The result is considered a hard blow to the socialist party MAS, which through former president Evo Morales has dominated Bolivian politics for the last 20 years.
During the day, elections were also held for the country's parliament.
