It's strange how millions of people saw that fight but a fraction know what actually happened. I've been boxing for 20 years now, and I come from a boxing family and we observed the same thing:
Floyd went into the bout thinking he was easily going to carry Conor--> Conor brings it to Floyd--> Floyd adjusts his strategy to gas Conor--> Conor punches himself out by the 7th round--> Floyd adjusts his strategy again to carry Conor for 3 more rounds-->TKO 10th
Conor has great boxing offense, period. His straight left is just as good as any world class boxer and he has power for days at his weight. But also simply put he knows how to throw a good punch and believe it or not that's kind of rare in MMA. However boxing is so much more than knowing how to throw a good punch. Floyd for sure underestimated Conor's ability to throw a good punch or better yet land one but like a world champion of his sport he used his entire skillset to completely outclass Conor where he is basically a novice by comparison.