According to Rock Lee, speed is bane of Neji's technique. At the stadium, Sasuke's speed was increased to the point that he matched Lee's 3rd or 4th gate. Also, with the sharigan sasuke could have seen the blindspot and with a chidori to the blindspot he wins
Dude don't lie to us, you're not the only one that reads manga, Guy said that sasuke speed was at the same level as lee's speed without weights, he never said anything about gates.
Plus unlike Lee, who was using pure speed, sasuke needed to use chakra to enhance his speed to that level because you can't naturally gain that speed within a month, that's why he had to finish the battle fast.
Another pointer is that rock lee's level of speed is not enough to beat neji, that's why Lee was saving the five gates for neji, sasuke's speed at that time was childs play to neji, although I will admit that with the sharingan's ability to predict the opponents movement, it could cause problems, but you must also realise that Neji has a FAR more superior strike speed with his 64 palms and 124 palms technique, sasuke doesn't have the speed to react to someone who can strike you 64 times in 3 seconds or 124 times in the same amount of time. Like rock lee said, predicting the movement is useless if your body can't keep up, sasuke may have a SLIGHT advantage in travelling distances in an 'instant' but neji has the advantage in stiking the opponent with rediculous reflexes from his 64 palms and 128 palms techs, and he has no blind spot, as far as everyone except dor kidomaru are concerned, close combat is taboo, sasuke will lose if he tries that.
Chidori is obviously useless against the rotation, naruto only survived because of his rediculous stamina and durability, otherwise he would have been out when he collided with neji INCOMPLETE kaiten, neji saifd that he wouldn't have enough time to activate kaiten just before he collided with naruto because he hadn't anticipated that much of a speed increase from the dobe, and there was no sphere when they collided, he was still in the process of activating kaiten when they collided, a complete kaiten has never been penetrated because it returns the full force of the opponent's attack back at them, naruto got lucky that's all.
Sasuke at the level he was at the time could not have hoped to defeat neji, he had no chance. All his jutsu will be repelled and his taijutsu will be defeated with relative ease, his points will be sealed.
Sasuke has a better chance of winning with the cursed seal level 2, otherwise it don't look good for him.
