Toph got really, really good at landing on airborne objects and sensing things like an airbender. She even tagged Aang. Azula is agile, but she will not be too agile for Toph to handle at all; it's her blue fire and lightning that will be the problem, but given how damn precise Toph got with her earthbending and how well honed her metalbending has become, this will be an even battle that could go either way.
She threw up a rock wall and Tommy gunned the rockwall in Aangs general direction. Lets not overhype it.
Anyway, for the bonus Toph comfortably, she's a huge problem on her own.
For the first round Azula in a close one.