Zio expected to be able to outmatch Jessica in every way. After all, he was blessed with the powers of the Profound Darkness, and far more accomplished than the gypsy-looking mage could ever hope to be in the arcane arts. Not to mention he looked prettier and used better hair products than that s- ahem. Anyhow, he was better in every way that he thought to matter.
Sadly, he forgot about pandering. And, since he was to fight Jessica in a beauty contest, this was the biggest deal.
You see, while Zio in a one-piece brazilian bikini might have its niches as a fantasy (albeit all the wrong ones), Jessica's generous cleavage and more feminine-looking features (...) certainly brought her ahead, not to mention she has plenty of suits to appease to her public. As such, when Sten and Brahne began bludgeoning Zio for his clothing, nobody was surprised. Jessica herself didn't cause much of an impression, but apathy is enough to overcome searing pain.
And that was quite possibly the most pointless win Jessica ever garnered in the Duelling League. Zio, on the other hand, still can't go outside his quarters without wearing a burka under penalty of being lynched by angry mobs.