The winning pace in the Spartathlon breaks out to almost a perfect 9:00/mile pace. Think about that. That's essentially the same 4 hour marathon pace the majority of "middle of the pack" marathon runners shoot for (and fail to hit). What the majority of average marathon runners can't manage over the course of just 26.2 miles, he did for 152.
Nevermind the stops for food, bathroom and possibly a brief rest, he still had to deal with an at-times muddy course and a nearly 4,000 foot ascent during the race. In contrast, most marathons have less than 500 feet of cumulative elevation change over their entire length and are on asphalt.
That is absolutely amazing.