User blog comment:IamJakuhoRaikoben/Chapter 326: Natsu vs. Rogue, Review./@comment-112.198.77.189-20130406081457/@comment-4829046-20130406111405

Erza never had a serious battle with Natsu after the very first time, but your other point is correct but I guess these were mainly for comedy so don't really count as actual defeats since Natsu wasn't in serious mode.