An upset is a situation where the underdog wins against all odds--everybody's rooting for the other team, but they pull it off anyway. I think in this case it would be best to interpret it as any instance where a player overturns expectations with a surprise win, whether because it's an unknown beating a well-established player or because it was someone who was losing badly but made a surprise turnaround and came back for the win. I think this is a fair way to interpret the category, then:
And now I think you're getting at, Legendaryseeker--you mean someone who doesn't win, but makes the best show out of losing?
I thought it was a situation like someone nearly losing a battle and then turning everything around. o_o I guess Effercon's explanation makes more sense with what Wikipedia tells me an upset is, though.
And now I think you're getting at, Legendaryseeker--you mean someone who doesn't win, but makes the best show out of losing?