**Flávio Bolsonaro holds a consistent lead in runoff polling after surprising with 47% of valid votes in the October 4 first round to Lula’s 45%, forcing the October 25 showdown.** Multiple post-first-round surveys, including Datafolha, AtlasIntel, Ipespe, and PoderData, show the Liberal Party senator ahead by 4–6 points among valid votes, with averages near 52% for Flávio and 48% for the incumbent Workers’ Party president. Traders on Polymarket reflect this edge, pricing Flávio’s win probability above 85% while Lula trades in the low teens. Key influences include voter dissatisfaction with economic conditions and Lula’s approval ratings near 43%, alongside consolidation of right-leaning first-round support. Remaining factors include the final stretch of free television and radio advertising, scheduled debates through late October, and any late shifts among undecided or blank-ballot voters. The race remains sensitive to turnout and campaign momentum in the final days.