Thoughts on the best fighter that an Australian boxer has ever faced, two ways you could approach this; 1.The boxer in mention was in their prime e.g. Hector Thompson vs Roberto Duran. 2. The boxer was either past his prime or hadn't become great yet e.g. Danny Green vs Roy Jones, Skinny Hussein vs Manny Pacquiao.
Taylor v Mosley Troy Waters v Terry Norris Troy Waters v Felix Trindad Kelly v RJJ Mosley, Norris and RJJ were all top 3 P4P at the time. Felix was Top 10 but not long after top 3
I suppose if you include amateurs as well, then no one would top Tony Madigan who fought Muhammad Ali. Followed closely by Athol McQueen vs Joe Frazier
That's the first that came to mind followed by Katz and Juan Manuel Marquez. French and nelson rates a mention
Fenech vs Zarate as well as Fenech vs Zaragoza probably rate a mention. Zarate is one of the greatest Mexican fighters of all time and while Fenech caught him at the end of his career, his name would carry as much weight as JMM.