Well, C was there first in that sense, but yes, you're broadly correct. But that misses the point. PHP was developed and released as a templating language - something anybody with a bit of basic HTML knowledge (and, frankly, all HTML knowledge was basic HTML knowledge back then) could use to build an interactive site by using HTML-like tags to employ code written by somebody else as widgets in an HTML page. Perl meant writing the whole thing, including emitting HTML from the code.
My ageing memory may be failing me, but wasn't Perl the first widespread language to be used for CGI ?