Hell's Event is a novelette written by Clive Barker. It was first published in the 1984 collection Books of Blood, Volume II.
Plot[]
Every one-hundred years, during an annual London marathon, Satan sends one of his representatives to compete against (unsuspecting) human runners. If Satan's minion wins, he gets to rule the Earth. An athlete taking part in the event, Joel, realizes the actual stakes of the race when the other runners begin to fall, savaged by some unseen beast. A satanist politician, Gregory, has made a bargain with Hell on the outcome of the race. Before he can win, Joel engages in a struggle with Hell's runner, who bites off his face. As they struggle, the last surviving human runner makes it to the finish line and Hell loses once again. Gregory is punished for his overconfidence by being gruesomely slain.