VIDEO: Derrick Williams hammers it home over Marreese Speights

Derrick Williams' dunk over Marreese Speights on Sunday night at Madison Square Garden was nasty, but not too nasty that you'd feel the need to turn your head away in disgust.

It makes you feel bad for watching it, knowing another human being was on the receiving end of a jam that will surely be immortalized on screensavers and posters everywhere.

Yet you can't stop staring. It's mesmerizing. Fascinating. Powerful.

Williams at his best.