those aren't ordinary 3 gennins, i hope you all know that.
1 is an uchiha member, trained by kakashi, and has incredible speed(everyone at the stadium were going insane by just looking at it)
1 is Rock Lee, trained by Gai sensei, we've alll seen his weights, he only knows taijutsu, can open alot of gates.
1 is Naruto, has demon fox chakra within him. by the way the sand shield wasn't in his way during that fight.

kitkat, i thought you didn't read the manga!! cover ur eyes!!