Call specific plugin update

I’m looking for way to update specific plugin via xmlrpc api. There is no exposed any function for do upgrades. I’ve tried to visit http://example.com/wp-admin/update.php?action=upgrade-plugin&plugin=plugin%2Fplugin.php&_wpnonce=b606ec1c5a (“update now” url from admin panel, _wpnonce parameter created by calling wp_nonce_url), but it gives only “Are you sure?” message. Sending post request to update-core.php?action=do-plugin-upgrade gives me this same: are you sure? Maybe there are some actions or some other ways for do that remotely?