User blog comment:IamJakuhoRaikoben/Chapter 457: Naked Battle, Review./@comment-26441125-20151019102926/@comment-26441125-20151019135928

The only fight in the series where Natsu doesn't win in the same battle sequence in which he started when was that owl assassin guy swallowed him in TOH. Again, not a real loss. Sure, he's been challenged, but he's never lost to a legitimate bad guy. (Exhibition fights with Erza are excluded from my criteria, btw, just clarification. Erza's said Natsu's just never won because he doesn't actually take them seriously.) Name a serious fight against a villain where Natsu legitimately lost, friendo, and I concede.