I read this years ago. A scout in spherical advanced ship lands on a planet. Natives are friendly, but the shaman perceives competition, and sneaks into the craft and scatters potions on the controls, their acid eating into plastics and metals. He can be rescued at the other side of planet, but he has a deadline. Eventually all make airship and he makes it.
The Flying Sorcerors by Niven and Gerrold is a humorous novel which has many elements in common with your description. One of the characters is a thinly disguised Isaac Asimov who conflicts with the native sorcerer for prestige. The native "magic" is based on potions, corrosive liquids, use of native animals, etc. His ship is destroyed in the conflict, and they do end up constructing an airship.
His egg-shaped (close to spherical!) spaceship is shown on this cover.