SAO PAULO, Aug 5 (Reuters) - Brazilian President Luiz Inacio Lula da Silva continues to lead Senator Flavio Bolsonaro, although the right-wing challenger has narrowed the gap with the leftist incumbent ahead of October's election, a Quaest poll commissioned by brokerage Genial showed on Wednesday.
In a simulated second-round runoff, Lula would receive 44%support compared with 39% for Bolsonaro.
A July 15 Quaest poll had Lula leading Bolsonaro by 45% to 37%.
In a first-round scenario, Lula would lead with 39% of the votes, followed by Bolsonaro (30%), Renan Santos (4%), Ronaldo Caiado (4%), and Romeu Zema (2%).
Senator Bolsonaro is the eldest son of former President Jair Bolsonaro.
The previous poll showed Lula at 40% and Bolsonaro at 28% in the first round.
If no candidate wins more than 50% of valid votes in the first round, the two frontrunners advance to a runoff.
Quaest surveyed 2,004 people between July 31 and August 3, with a margin of error of 2 percentage points.
