Lorenzo Pazolini (Republicanos) entered the October 25 runoff as the first-round leader with 49.65% against incumbent Ricardo Ferraço (MDB) at 34.06%, a roughly 15-point gap that left traders pricing Pazolini as the favorite for victory but uncertain on margin. Recent campaign moves—Pazolini’s October 7 Brasília trip to consolidate national alliances and Ferraço’s October 6 meeting with more than 70 local mayors—highlight both sides’ efforts to secure endorsements and municipal structures ahead of the vote. The 15.32% won by eliminated PT candidate Helder Salomão, combined with elevated null votes and low first-round turnout patterns, creates competing scenarios for vote transfer and final spread. Pre-runoff polling had shown Ferraço competitive or ahead, yet the actual first-round result shifted implied probabilities toward a Pazolini win of modest to double-digit size while leaving substantial probability mass on narrower or wider outcomes.