Germany's Pascal Ackermann was second and Italian Simone Consonni came home third.
Ecuador's Richard Carapaz retained the overall leader's pink jersey.
Cima was one of three breakaway riders and he gave a final push as the main bunch came breathing down his neck, holding off German champion Ackermann for the win.
Friday's 19th stage is a 151-km hilly ride from Treviso to San Martino Di Castrozza.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
(Writing by Julien Pretot, editing by Pritha Sarkar)
Share
