Before she lost control, Rainbow's stunt was genuinely amazing while it lasted.
Twilight reluctantly pulling out her princess status, to prevent Rainbow Dash from being sent to the Canterlot Mental Hospital.
Later, when she stands up to Celesta herself, for the same reasons.
After Rainbow Dash gets her memories back in Raising Rainbows, Scootaloo (Who isn't aware of this at the time.) asks her if she wants to play, while Twilight goes to save the day. Rainbow immediately makes it clear, that she's back.
A more subtle example from a little later; Twilight reducing a pack of timberwolves to splinters within a second.
