Pre-Crisis Cassandra Cain vs. Charles McNider version of Dr. Mid-nite in his physical prime. Standard Rumbles defaults.
I think the key question is how reliant Cass is on her body-reading ability. She had trouble fighting the Joker because she couldn't read him, so in in theory, she should have a problem fighting blindly against Dr. Mid-nite.
On the other hand, Cass has a definite speed and skill advantage over McNider.