It had me hooked.
As far as grammar goes, a problem that I noticed is that you mess up your "its" versus "it's". "Its" is the possessive form, to show ownership. "It's" is the contraction for "it is".
Other little things:
The finalists were the notorious Han Black, believed to be the mastermind behind many computer viruses and worms, helped by his trusty Virtual Pokemon, Porygon2, and his opponent, a 14-year-old boy called Shade Gaskin, who hailed from Hearthome City in Sinnoh, who was absolutely creaming the competition with his well trained Magnezone.
Length for this one sentence is the issue here. Too long, trying to pack too much information into it. If either Han Black or Shade Gaskin are characters showing up again, you could stick the information about them not related to the battle there. Right now, for this battle, all we really need to know are names and Pokemon. Maybe location, but certainly the first two.
All I really noticed. Like I said before, this had me hooked. I couldn't turn away from the screen, engrossed in the battle. Good luck with future installments/versions of this, and hopefully I'll be able to catch this here soon.