UPS Question - Watts

Would I be able to use

http://www.cyberpowersystems.com/products/ups-systems/intelligent-lcd-ups/cp1350avrlcd.html

for my Dell 2900 server (930W power supply)

Its rated for 810W so I realize I'm asking more out of it than its saying but will it still work for a little bit do you think or will it only last for a second?

Thanks