your right but to specify on what your saying sasuke fought against him and killed part of him and the other part was sealed with sasuke's cursed mark seal.. then when sasuke fought against itachi, itachi waited for ori to come out wich he did when sasuke sumoned the giant snake then itachi used used his susanoo to finish him off.
p.s. i wasnt trying to sound like a jerk or anything for specifying on your reply Frederick Uchiha i just felt like going into details.