I guess that does sound like more than just "play fighting".Sorry for the late response. There was no fur flying or bleeding from what I recall. There was a lot of rolling and shrieking before Sapphire managed to get away and Fluffy was hissing/arched back/puffed up tail.
Can't remember if I've posted this article link before, but there's videos and pics showing the difference between play fighting, and actual fighting. Are My Cats Fighting Or Playing? – TheCatSite Articles