User blog comment:Phoebus18/Who's strongest Dark Mage?/@comment-147.226.184.245-20131216202904/@comment-7418318-20131217132549

Made quick work? You must have read another manga/seen another anime than me... because in the ones I saw, Jellal was about to obliterate Natsu together with the entire tower and was only stopped from doing so by the wound Erza gave him.

So Natsu barely defeated Jellal after Jellal already was exhausted and hurt by Erza, while Zero was quite fresh in his battle against Natsu.