UPDATE: Justin Bieber won! Vote for him in the Championship Round here.

The semifinals of the Hottest Star of 2013 are about to get swagged out! Justin Bieber and Austin Mahone are competing to take claim the title for hottest male celeb.

In the first round, Justin Bieber beat out One Direction's Harry Styles by less than 1 percent! What can we say? Bieber isn't messing around! JB is known for cranking radio-friendly hits, as well as numerous collaborations. His latest duet with Miley Cyrus, 'Twerk,' is getting a ton of buzz!

Austin Mahone is definitely a force to be reckoned with! Last round, he ousted Australian sweetheart Cody Simpson. This looks to be Austin's year; at the 2013 MTV VMAs, he was awarded the Artist to Watch honor. We're not surprised -- his 'What About Love' has all the ladies swooning!

Which of these singers is hotter? You can vote once an hour until the polls close at 2PM ET on Sept. 13.