Anyway, back on topic cause that isn't a rule that's been modified, I would, for the time being, have to agree with Aura7541 concerning the bolded question. That's the best I can remember at the current moment. And Ash also had Pikachu "cheerlead" for Dawn during her contest in "Playing the Performance Encore" if my memory serves (not sure if it counts the same, but it happened). I really find it hard ATM to pick out a specific moment; I just really like their chemistry overall more than any other pair of Ash and a traveling companion. They just seem much closer.