Polish lancers and light horse against a German transport column near Rypno on 9th September 1939? Similar charges by the Poles later in the war are supposedly just myths but I think this one actually happened.
I could dig out the bit of my Dad's memoirs where the Polish POWs comment that everyone knew they were tanks (it is also said that the German tanks were canvas covered decoys) but hey charged them anyway to show they were not afraid.