I don’t have any good examples that I know of, but I am very curious. To me though, a rivalry is a rivalry when two or more of people are closely competitive. But is it really a rivalry anymore when someone has more victories over the other? I don’t think so.
If we’re talking football ⚽, a rivalry is usually a long term thing, that transcends temporary factors like winning records.
You only have to look at Liverpool and Everton, or Man City and Man United, or Aston Villa and Birmingham City, to see that rivalry can be fierce and lasting even when one side enjoys a long period of dominance over the other.
As long as it matters more than most games to both sets of fans, it’s a rivalry IMO.