Ohhhhhhhhhh, I've been thinking about that one for 39 years !
Hard to miss that match-up, as, after all (off all things !), they were both after the same guy
I'd see it taking place on the bridge of the ''Galactica'', as on those last shots
Athena (turns back and sees her): ''... what the frak are YOU doing here ?''
And, on the last shot, they really do seem to be about to finally ''settle'' the matter
In a ''straight'' fight, Athena wins, as, beyond just my plain ''feel'' of the two, she does seem a bit tougher and, being in the military, she must have had some hand-to-hand combat training, where as Cassiopeia did have a certain ''ditsy'' side at times...
... however, with Cassiopeia being a ''socialator'' (hooker, prostitute, escort...), if she should decide, seeing that Athena, after a while, has got ''her number'' in the fight, to turn the fight naughty, if only via a boob-fight, or such (or an all-out sex-fight-like battle), then it's Athena who'd be 'toast''