Rava considered Rav Sechorah his "Rebbe" for all of the legalities imparted by that status, because he taught him a single set of laws: Bava Metzia 33a
Rava praised Rav Nachman to Rav Sechorah as a great person: Nedarim 22b
Rav Nachman attempted to find a way to rescind a vow of Rav Sechorah's, and when he was unable he told him, "Go home!" at which point Rav Sechorah used that as the means of rescension of the vow [as he had caused a great man to say that to him with his vow, which was not his initial intention]: Nedarim 22b