Congratulations to 5 Seconds of Summer! The group of Aussies beat out the Vamps in the last round of Pop Clash with their heartbreak hit 'Amnesia.' This time, they are facing off against fellow Aussie Iggy Azalea and her smash 'Fancy'. Which song should win this week's Pop Clash?

5SOS' 'Amnesia' is not only the perfect breakup song, it's also a more mellow, heavier tune than their tune 'She Looks So Perfect' -- and while both songs are amazing, we love that the group can nail such a wide range of emotions so perfectly. It's clear that the guys' feelings run deep on the track, and we're obsessed with their harmonies. The lyrics of the song may make us cry, but we're still simultaneously swooning over the band.

It's safe to say that Iggy Azalea's 'Fancy' has been in our heads all summer long -- and let's just say we're not complaining. We love the badass edge in her voice as she spits verse after verse on the addictive track, and with Charli XCX on the insanely catchy chorus, we just can't get enough.

Which song should win this week's Pop Clash? Cast your vote for 5 Seconds of Summer or Iggy Azalea once per hour until the poll closes at 3PM ET on Monday, July 21.

Listen to 5 Seconds of Summer's 'Amnesia'

Watch Iggy Azalea's 'Fancy' Video