Neji definitely wins this fight. Sasuke only had 2T sharingan and had the LVL 1 curse mark to help him at that time. Sasuke won't have the predicting abilities of a 3T sharingan, and Neji was able to keep up with naruto in his initial jinchuuriki form. Neji's taijutsu was the greatest of all genins at the time, and Sasukes chidori wouldn't be able to penetrate nejis defense. All in all, neji would no doubt win this fight