Kakashi is a pretty skilled ninja and he definitely deserves some credit for mastering many of the Sharingan’s secrets. That being said, an Uchiha can only be defeated by an Uchiha. This isn’t an absolute, but it’s typically the case thanks to the limitless powers of the Sharingan. Itachi is more proficient at using it and Kakashi would not be able to win in an eye battle. Kakashi’s Lightning Blade would be very dangerous, but Itachi’s Susanoo should be more than enough to protect him. Itachi wins.