What was the first song with a rap verse to hit #1?

If you're a fan of the Wu-Tang Clan, you have a blonde new wave singer to thank for introducing some members to rap. Actual hip-hop couldn't get mainstream radio play in the early '80s, but Blondie could. Debbie Harry and bandmate Chris Stein were spending time with Fab 5 Freddy out in the Bronx, and by 1979, they figured they'd try writing their own rap song. That's how "Rapture" came about, but I have no idea why the song is about a man from Mars eating Cadillacs and Subarus. The track hit number one in March 1981 and made Blondie's rap verses the first to top the Billboard Hot 100 (it would also be their last time topping the chart). It took almost another decade before an actual rap song topped the charts, and of all people, of course it was this one.