I just did negative seo? Target website disappeared from SERP

So I've took an article that was ranking on page 1 position 4. Their website is quite authority, it has 500 RD to the homepage, tons of articles and traffic, they also run an adwords campaign. DA 35. Domain strenght on Ahref is 43.

What I did: I rewrote one of their articles that was ranking on position 4 for a certain keyword. It took me 10 days to rewrite it (I was a bit lazy). I'm sure I did a great job rewriting it, and it pass the copyscape check.

Then I finally published the article…

I just did negative seo? Target website disappeared from SERP