Alivia had a lot more Power to play with, but we already know raw strength is a lot less important than skill. Cyndane knows far, far more about channeling, and she was able to see every weave that came her way. This means that she could both slice/interfere with Alivia's attacks, and she would quickly have got an idea of her abilities and strategy. And I don't care how good damane are at destroying things, they are not trained to be creative, adaptable or to show initiative. She would have been ferocious but single-minded, very predictable and easily tricked.

Alivia's only advantage in that battle was her unravelling ter'angreal, and it only stops direct attacks. All in all, Cyndane should have been able to kill Alivia with little difficulty; you can't stop a weave you can't see - or at least, Alivia doesn't know how to do so - and I can think of a dozen nasty ways of killing someone that don't require direct weave-contact. Cyndane undoubtedly knows many more. Alivia couldn't have seen them coming, couldn't have defended against them, and shouldn't have survived two minutes of concentrated attack.