The poll, conducted by the Poderdata institute and published on the Poder 360 website, assured that Lula has 52 percent of vote intentions, while Bolsonaro has 34 percent.
In the previous study, the former president had 41 percent, compared to 36 for Bolsonaro.
Lula also leads in the simulation of the first round of presidential elections.
In this case, he would won 34 percent of probable votes compared to 31 percent for Bolsonaro.
The survey included 3,500 interviews and was conducted from April 12 to 14. The margin of error is more or less 1.8 percent.