It had nothing to do with the video.
Just when you thought Rihanna's TWO new "Work" videos were her ticket to another number 1 on the Hot 100, Billboard has announced that the song will be taking the top spot THIS week, meaning it rose to the top without the help of VEVO streams.
This is Rihanna's 14th number 1 on the Hot 100, pushing her ahead of Michael Jackson's number (though she's still behind Mariah Carey and The Beatles). It also serves as Drake's second number one, the first fittingly being his 2010 duet with Rihanna, "What's My Name".
Despite releasing a few singles since, this is the singer's first #1 since her 2012 single, "Diamonds".