The survey by Datafolha showed Lula with 45% of voter support against 32% for Bolsonaro in the first round of the election scheduled for Oct. 2, compared to 47% and 32% respectively in the previous poll.
In an expected second-round run-off, Lula would get elected by 53% of the votes versus 38% for Bolsonaro, a 15 percentage point gap, down from 17 two weeks ago, the poll showed.
For political analyst Sergio Praca, the results of the second round results could swing either way.
On the streets, people's opinions are torn. While some, such as storekeeper Raimundo Pereira, see Lula as the clear winner, others like taxi driver Sergio Praca would like to see Bolsonaro remain in power.
Datafolha interviewed 5,734 people in person between August 30 and Sept. 1. The poll has a margin of error of 2 percentage points.