Since the dawn of Hollywood, celebrities have developed long standing, intense rivalries that raged until their dying days. Now we have a new one, and it's awesome.

Peter Sellers and Orson Welles hated each other so much that their casino showdown scene in the James Bond parody comedy 'Casino Royale' were filmed separately with doubles standing in for the other person.

Donald Trump and Rosie O'Donnell have been at each other's loud throats since she criticized him for reinstated Tara Conner's Miss USA crown after photos of hard partying days surfaced and she had to go to rehab for drug abuse.

Two guys named Kramer were so spiteful of each other that Hollywood made a movie about it: 'Kramer vs. Kramer.'

Apparently, Justin Bieber and late night show host Jimmy Fallon have developed one of their own. Since the two have new albums vying for a higher spot than the other guy on the charts with Bieber's 'Believe' and Fallon's 'Blow Your Pants Off,' it seems that they have developed a bit of spite for each other. However, unlike most gutless celebrities who let petty jealousy and meaningless competition get in the way of each other, they decide to settle it once and for all.

So the two staged a series of competitions to determine who is more awesome on Fallon's show. The challenges range from a quick game of 'NBA Jam' on Fallon's Xbox to the world's most intense game of 'Rock, Paper, Scissors.' Who will come out on top? There's only one way to find out.

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