Harry Styles served as both host and musical guest tonight on Saturday Night Live and, ahead of his performance, Erskine/Columbia released a new track, "Watermelon Sugar," which he performed on the show.

It has already hit #1 at iTunes (where his forthcoming album is in pre-order; see below) and Top 5 at Spotify U.S., while at Spotify Global it's entered the Top 15.

In addition to his musical segments, the British superstar delivered the opening monologue (in which he saluted One Direction and expressed his gratitude that Simon Cowell "grew us in those test tubes") and appeared in several sketches. Styles' big night follows the trend of other stars pulling double duty in recent seasons of the show, namely Chance the Rapper, Halsey, Donald Glover/Childish Gambino, Ariana Grande, Drake and more.

Styles will release his second album, Fine Line, on 12/13, and will debut it live that night at The Forum in Los Angeles.