I would like to understand the rules of this match more, because it has been made too broadly. In either case, allow me to set scenarios and outcomes.
The first would be if the OP meant that they are boxing, and boxing only. That means no kicks, no chakra molding, no jutsu (ocular included,) and no leaving the confines of the ring. In this scenario I believe that Naruto would beat Sakura because she does not have the stamina OR endurance to go blow for blow with Naruto (remember, she is not using her byakugou or healing techniques, and she is not molding her chakra to enhance her strength.) It would be the taller, faster, stronger chinned Naruto exchanging blows with her and ultimately knocking her out, and for those that might argue that Sakura can "predict his attacks and dodge them because of her training with Tsunade" there is only so much room to dodge inside of a ring. She would be forced on the defensive and pummeled.
Sasuke is at a severe disadvantage because he only has one arm. He also cannot use his sharingan or chakra for shunshin, so all that he has is the reach of his one arm. I think that Sakura will beat him in a drawn out fight for the mere fact that she has more chances for a fist to land than Sasuke does, and seeing as his left arm was his dominant arm, the best that could happen is he attempts to dodge while doing the most damage he can with flicker jabs. Sakura rushes him with both arms up (like Ippo or Tyson) and pummels. Sakura wins against one armed Sasuke.
This is the "straight fisticuffs" version of how I see these match ups. Would the OP like to add more restrictions/rules to the fights? If not, this is how I see both matches ending.
What do you think?