In the '60s, the Young Rascals' "Groovin'" charted Soul as well as Hot 100. In the '80s, "Easy Lover" charted Soul as well as Hot 100 even though the song was rock/pop in typical Phil Collins style; Phillip Bailey just sang a verse, which didn't change the fact that the genre of the recording wasn't R&B. (Note: Forgive me if I don't have the correct names that Billboard was using for what is now its Hot Urban chart. At various times, it was Hot Soul, Hot R&B, Hot Black and heaven knows what else.)
Oh, and Hall and Oates' "Sara Smile" was a top 10 hit on the Soul/R&B/Black chart. It was a soul ballad with two white guys singing, just as urban as anything else on that chart back then.