So honestly have you known that? Yes, Black Magic Woman by Santana is only a cover version. The original song was written two years before by Fleetwood Mac.
However, Black Magic Woman became really famous in the version by Santana. And it is one of the hits from the wonderful and perhaps best Santana album Abraxas. But you should also listen to the original by Fleetwood Mac, it is a great song, too.