Naruto and Kakashi vs Itachi
This is when Naruto has fully mastered his wind element and knows the wind rasengan. During Shippuden time.
Naruto: a ninja of the hidden leaf village who has mastered his element. He knows and ultra ninjutsu called the rasengan which is a ball of spiraling chakra. He has defeated one akatsuki (along with some help I believe) and is still a Genin.
Kakashi: a ninja of the hidden leaf village. He is a Jonin, which is the top level ninja in the village, which is where he focuses his elemental chakra to his hand (which is lightning) and strikes his opponent. He has a very powerful ninjutsu called the lightning blade. He also can use the sharingan.
vs.
Itachi: a rogue ninja from the hidden leaf village. I believe he became a Jonin at 13 years old. He is from the Uchiha clan. He killed his whole family except for his little brother Sasuke, who eventually kills him. He has the Mangekyou sharengan, the most powerful one there is and is a master of genjutsu. He is now a member of the akatsuki.