How stupid must you be to think that you can win against Nanoha?
Nanoha's got ridiculous firepower, but Sayaka's fast and basically invincible until her soul gem is destroyed or corrupted. Nanoha can wear her magic down easily by hitting her hard and forcing her to use it on regeneration, but Sayaka also just needs to get in close and make it past her barrier(s). Seems like a relatively fair fight.
Oh, filename. Fuck it.