Brazilian Senator Flavio Bolsonaro and President Luiz Inacio Lula da Silva are statistically tied in a simulated runoff ahead of next month’s election, an AtlasIntel/Bloomberg poll showed on Thursday, with the right-wing lawmaker now holding a narrow numerical edge over the leftist incumbent.

The eldest son of former President Jair Bolsonaro would receive 46.4% of the vote in a second-round runoff, compared with 46.2% for Lula, the poll showed.

In late August, Lula led the senator 47.1% to 42.6%.

In a first-round scenario, Lula is seen leading with 43.0% of the vote, followed by Bolsonaro (37.4%), Augusto Cury (6.6%) and Renan Santos (6.5%).

The previous poll showed Lula at 43.4% and Bolsonaro at 33.7% in the first round.

If no candidate wins more than 50% of valid votes in the October 4 first round, the two frontrunners advance to a runoff on October 25.

AtlasIntel surveyed 5,000 people between September 4 and 9. The poll has a margin of error of 1 percentage point.