I read the books years ago and in my language, Spanish, with diferent tittles, so I don't remember exactly which book they were in, but surely the two fights happen in that saga.
One of them is in Cesar's life, while he is in Gaul and the two lovers of a barbarian chief fight. The other is after Cesar's death and his lover, Servilia (Bruto's mother) and her daughter-in-law, Porcia, fight.