Force Mac OSX to restart instead of waking up
You can hold down the power button for 10 seconds, wait a couple seconds, then press the power button again and it should boot.  However, if the computer battery is still dead, it may take a few minutes before the battery will charge up enough before the computer will boot.  

So, once the battery has had enough time to charge up from dead (~5-10%) it should allow you to restart it.