Not reliably.
You could set up a node instance to request the page, and run server-side JavaScript against the http response, but that wouldn't be anything like running a script in a browser window that can interact with the scripts that the page runs, and the assets it pulls in from other URLs.
To fire an event on a page it would have to be loaded into a browser. You could speed things up with Phantom or another headless browser though.
I'd recommend the latter if you want performance and quality over greasemonkey any day. It's a little more complex, but if this is an ongoing comparison automating it into the background and away from a rendering browser seems best.