The Secret Triwizard Challenge

You hit the spider in the head with Flipendo. The spell only forces its head back, not the rest of its body, and cracks the spider's neck (do spiders have necks? Either way, the spider is basically decapitated at this point.). The professors will find a spider's corpse in the morning, but that's a problem for another time. For now, you're safe.
You run to the exit and into the maze. You can still win this.