When you are "in the zone" and youre dealing with the situation instant by instant, then there really not need be such thing as a combo; that is, its not planned--its just the next strike you throw, based on the way the situation keeps unfolding.
If you have clearly better timing than your opponent, then you can go from a place of defense to a place of offense and maintain control. If his timing is better, then youre just trying to hang on til the end!
In the video above, theres a lot of significant gaps of ability between Sugar Ray and his opponents, so he is always controlling and dominating. And sometimes the skill level is closer, so there is more back and forth.