I too once started an essay 4 hours before it was due, but it was only a little 1000 worder, and it was only for philosophy. I did 0 research for it (you can pull that off pretty easily in philosophy) and for my bibliography just chose a few random titles from the reading list. I just got it in on time. Got a B- for it.
Oh and there was the time I had a mini-essay for high school economics due in the class that came after our lunch break. I did the essay during lunch and got 20/20 for it. It was worth 10% of the year's mark, and I finished that course right on the pass mark. One mark less and I would have failed.