Ronda Rousey defeated Miesha Tate by submission in the 3rd Round in UFC 168, and after the fight, Tate offered a handshake to Rousey. Rousey wanted no part of it.
According to ESPN's Josh Gross, this shouldn't have been a surprise to anyone.
Here's a shot of the armbar that ended the fight. Rousey improved her record in UFC to 8-0.