Zhou was far from a trainee when it came to learning the give and take of combat.  Given the way she was attacking, he knew there was a reason she was leaving so many openings.  By the same token, he was also more experienced in how to attack from multiple angles than she was.  So during one of his retreating movements, he'd drive the lightning that was his zanpaktou down into the ground in front of him, sending it surging beneath the ground to shoot up from her very feet towards her.