How many times have MMA guys and boxers fought (for a belt) twice in a row?

I think Dana White robbed Anthony Pettis on making him wait on a shot at the UFC belt. Maynard had his chance and failed. I know Maynard has beat some tough guys, but he had his chance....twice. With the talent in this weight class, he should have to beat someone else up before he gets another crack at it. So with that said, how often after a draw, have fighters fought each other again without a different opponent in between?