In the finale of The Godfather: Part III Vincent's "clearance" of the Corleone family's enemies and the assassination attempt on Michael is intertwined with the family attending a performance of the opera Cavalleria Rusticana (in which Anthony performs). Additionally, the German Wikipedia article says that the movie also cites many images and plots of this opera (Vincent biting into Zasa's ear comes to mind).
But having only very superficial Wikipedia-based knowledge about the story of the Cavalleria Rusticana, I have difficulties to draw any further connections of it to the movie. Now while I don't want this question to get too broad or degrade into a mere list of each and every possible camera shot referencing the opera, I'd like to know if there are any major references to the Cavalleria Rusticana's story or its overall motifs in the The Godfather: Part III.