The question has already been answered.
That was just hi speed movement. It was not a Space-Time jutsu (like FTG) because:
-Bee saw a trail of Naruto's movements
-He got his foot stuck in that wall
If it was a Space-Time jutsu, he would have just appeared there, and none of the above would have happened.
When they say that he is not on the 4th's level yet, they are talking about his speed, and about his control.
And he got that speed because of the Kiuuby chakra that he uses and goes around his body like an aura or something. It enhances both speed and strength, and who knows what more, just like sage mode.
We know that the body Flicker depends on the user's chakra, and how much chakra he puts in the jutsu, and we also know that Naruto has huuuuge amounts of chakra while using the kiuuby's power so that's where that insane speed came from.
Oh and this also might help you better understand:
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