Qualifier Valentin Vacherot defeated his first cousin Arthur Rinderknech in the final, 4–6, 6–3, 6–3 to win the singles tennis title at the 2025 Shanghai Masters. It was his first ATP Tour title, and he defeated five seeded opponents consecutively en route. Vacherot became the first Monégasque player to win a tour singles title, the first unseeded champion at the Shanghai Masters, and the lowest-ranked ATP Masters 1000 champion. Vacherot was the third qualifier to win a Masters 1000 title, and the fifth player overall to win an ATP 1000 as their first tour-level title.