Yes, via SSH. Set up
openssh-server on your computer to proceed. Next, have a look at this page to find the appropriate command to invoke the suspend. You could simply use
sudo pm-suspend, however, this requires root priviliges.
Now, turn the suspend command into a Bash alias by adding the following to your
alias suspendnow='dbus-send --print-reply --system --dest=org.freedesktop.UPower /org/freedesktop/UPower org.freedesktop.UPower.Suspend'
Save, log out and back in again.
Now, if everything is set up correctly, you could run:
ssh user@computer -f 'suspendnow'
to initiate the suspend of your computer. Note, this might not work on a server, you'll have to use
sudo pm-suspend instead of the fancy dbus method.