Signs of imminent attack:

Widening or “blackening” of the eyes (dilated pupils), ears turned or laid back, twitching tail, whiskers flattening against the face.

Never try to restrain the cat. Stop petting and remove yourself (especially vulnerable face and hands) from your cat’s reach. If possible, offer up a throw pillow, toy, or socks to redirect your cat’s attention/aggression. To avoid future incidents, mind that feline body language. Chances are your cat is telling you he’s had enough and you’re just missing the signs.