Britney Spears has defeated Christina Aguilera in our first-ever Throwback Thursday battle! It was a close race, but Brit's breakthrough hit '...Baby One More Time' managed to overtake Xtina's 'Genie in a Bottle,' garnering more than 51% of the fan votes. Congratulations to Britney and all of her fans that voted!

For this round, reigning queen Spears will take on ex-boyfriend Justin Timberlake as she challenges his boy band 'N Sync and their smash hit 'Tearin' Up My Heart.' Will '...Baby One More Time' be able to stand up against the sweet harmonies of 'N Sync's ultimate sing-along jam?

On Britney Spears' '...Baby One More Time,' the songstress manages to combine bubblegum pop beats with oh-so sexual lyrics. While her innuendos are more on the sly, this mega hit definitely had some parental units worried back in the late '90s. In between her seductive "oh baby baby's," Spears coos, "My loneliness / Is killing me (and I)  / I must confess  / I still believe (still believe)  / When I'm not with you I lose my mind  / Give me a sign  / Hit me baby one more time."

On the other hand, JT, JC, Joey, Lance and Chris were teaching us a thing or two about the troubles of love with their breakout hit. The boy band won over the hearts of millions with their funky beats and woeful singing on 'Tearin' Up My Heart,' with Chasez taking the lead as he croons, "Baby I don't understand / Just why we can't be lovers / Things are getting out of hand / Trying too much, but baby we can't win."

As if the song wasn't addictive enough, the wind-swept, tightly choreographed video had us 'N Sync lovers fanning ourselves from hotness overload. JT singing in a skintight tank atop an empty bed? O.M.G.

Which throwback jam is your favorite and keeps you grooving along to this day? Vote for either Brit's '...Baby One More Time' or 'N Sync's 'Tearin' Up My Heart' below! You can vote once per hour until the poll closes next Wednesday, March 13, at 11:59 PM ET.

Watch the Britney Spears '...Baby One More Time' Video

Watch the 'N Sync 'Tearin' Up My Heart' Video

Rules of Throwback Thursdays: The artist and song with the most votes wins, and the winner goes on to face a different Throwback Thursday challenger the following week. If an artist wins four weeks in a row, they will be retired into the Throwback Thursdays Hall of Fame in order to give others a chance to compete.

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