that's wrong, baby washington was '63, pat thomas is '64. I saw that on the pat thomas record one of the writers produced it (versus juggy murray) but back in that time, songwriting was a full time profession, songwriters shopped songs around trying to get a producer to pick it up... although I don't know what specifically happened in the Baby Washington case. Even if the songwriter decided to later produce the song on an artist, it's not necessarily first.
also, even if pat thomas was first, baby washington had the hit.