You can make a case for JCC, Pryor, or Chavez being the best at that weight. All great fighters. But in his prime...i wouldn't bet against Tszyu against anybody at 140. Tremendous power, skill, and intelligence. As The Third Man already mentioned...he wasn't physically right in the Phillips fight. The Hatton fight was a combination of age and horrible refereeing. Not trying to make excuses for Kostya...just don't think he was at his best for those two fights. My dream fight has always been Tszyu vs. Mayweather in their primes. That would have been a tremendous fight!