Why dont these two lines of htaccess both work at the same time?

How do I make the second line redirect internally?

RewriteRule ^([0-9]{4})\/([0-9]{2})\/(.*)\.html$ /$1$2-$3 [R=301,L]
RewriteRule ^([0-9]{4})([0-9]{2})-(.*)$ /$1/$2/$3.html [L]

Code (markup):

I've been trying to figure it out for ages!