UPDATE: Lady Gaga won! Vote for her in the Championship Round here.

It's the semifinals of our Hottest Star of 2013, and we've got Rihanna up against Lady Gaga. Wow. Let's just say that's a lot of personality fighting for the title!

Rihanna exudes sexiness, which we lurve. She's confident and has a toned body, so why not work it! Her RihannaNavy knows this, and made sure that Rihanna won Round 1, beating out the bootylicious Beyonce by a very small margin. But can she take on the little monsters?

The Mother Monster is on fire right now, promoting the hell out of 'ARTPOP.' She's not afraid to show skin and a more artistic sex appeal. She's also been going more au natural with her hair as of late, which suits her and her music. And her little monsters have been behind her every step of the way, as she managed to beat Katy Perry by less than 1% in order to move on to the semifinals!

Who gets your vote for the Hottest Star of 2013? You can vote up to once per hour below until this poll closes on Friday, Sept. 13, at 2PM ET. So, what are you waiting for RihannaNavy and little monsters -- Go!