Katy Perry 'Dark Horse' remains on top of Billboard Hot 100, as viral videos boost 'Say Something' and 'Let Her Go' [WATCH]

Katy Perry's "Dark Horse" is striding strong. The surprise trap-infused Prism hit is going to spend a third week atop the Billboard Hot 100, but she best watch out: Pharrell is singing a happy song right behind her.

The dominance of "Dark Horse" was elevated this week, easily securing the No. 1 spot in the US. According to Billboard, the Juicy J-featuring track topped the Digital Songs chart for the fifth week in a row with 291,000 downloads sold, reached 132 million people on the radio, topped On-Demand streams and held strong on the Streaming Songs.

Despite that massive success, Pharrell's "Happy" is right on "Dark Horse"'s tail. Thanks to some highly visible Beats By Dre ads and that infectiously peppy beat, the Oscar-nominated Despicable Me 2 song launched up the charts, vaulting from No. 8 to No. 2. "Happy" got massive boosts in downloads (252,000), a five position raise on the Radio Songs chart to No. 10 and was streamed 3.7 million times last week, giving the Grammy-winner something to be "Happy" about indeed.

And fun fact: "Happy" is the highest-charting Oscar-nominated song since Eminem's "Lose Yourself" reached No. 1 in 2002.

Jason Derulo is riding dirty in the top 10. His latest single "Talk Dirty" keeps riding that viral video "Celebrities Talkin' Dirty" train to the charts, rising yet another spot this week to No. 3. With 242,000 downloads sold, a rise in streaming and a slight rise in radio (now sitting at No. 17 on the Radio Songs Chart).

Passenger's "Let Her Go" found a new chart height this week, reaching No. 5 thanks to the adorable, heartbreaking Budweiser ad from the Super Bowl, wherein a horse and puppy refuse to be apart. Thanks to a good ol' animal love story, the track saw an increase in downloads, streams and radio play to reach the chart's top 5.

The rest of the Hot 100 features familiar fare for this winter season. A Great Big World's "Say Something" (feat. Christina Aguilera) rose three spots to No. 4, snuggling between "Talk Dirty" and "Let Her Go." Billboard notes that the songs three spot jump comes courtesy of a viral video, wherein 4-year-old Jackson is moved to tears by the song, thus moving the nation to tears.

That boy is going to grow up to be a poet, btw.

The top 10 is rounded out by Pitbull and Kesha's "Timber" at No. 6, OneRepublic's "Counting Stars" at No. 7, Beyoncé and Jay Z's "Drunk In Love" at No. 8, Lorde's "Team" at No. 9 and Bastille's "Pompeii" at No. 10.

This means that after an insane playtime in the top 10, Lorde's "Royals" has finally been removed from power.