Two of pop music's biggest artists are battling it out in the semi-final round of Hottest Star of 2014! After just managing to beat out One Direction in Round 1 with 50.17% of votes, Justin Bieber is now going head-to-head with 5 Seconds of Summer, who dominated over the Vamps in Round 1 with over 70% of votes. Which top pop act should move one step closer to being crowned Hottest Star of 2014?

Justin Bieber may have been in the news more for his behavior than his career this year, but that hasn't stopped him from remaining one of the hottest pop acts in 2014. Bieber is always in the studio working on new music (whether it's with Austin Mahone, Cody Simpson or by himself) and wrapped up a worldwide 15-month tour. Not to mention that he even helped save a little boy's life -- and if that isn't worthy of the title of 'Hottest Star,' we don't know what is.

5 Seconds of Summer exploded onto the scene this year, with their pop-punk infused hit 'She Looks So Perfect' causing millions of girls to fall head-over-heels for the Aussie band. The 5SOS frenzy is only getting stronger as the year goes on, with the band's self-titled debut album hitting the U.S. next month and the guys supporting One Direction on their worldwide Where We Are Tour. One thing's for sure: Even after the summer ends, there is still no stopping 5 Seconds of Summer!

You can cast your vote for Justin Bieber or 5 Seconds of Summer once per hour until the poll for this round closes on July 7 at 12 PM ET. The winner of this round will move on to face another competitor in the final round, and will be one step closer to becoming crowned Hottest Star of 2014. Now get to voting!

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