How do I do simple flat link to .php file redirect?

My current .htaccess file is as
Options +FollowSymlinks
RewriteEngine On
RewriteRule ^(.+)\.html$ $1.php [L]​

This is at the directory level, I do not want to have a site-wide .htaccess.
I […]

See original post by invalid@example.com (mrtdmb)