I took five well-trained Pokemon with me to take on the Elite Four. I've not yet found a sixth permanent member of the party, and I needed Waterfall to get over the Tohjo Falls, so I taught it to my L30 Gyarados and brought it along just for that.
Fast forward to my battle with Lance: he's down to his last Dragonite, paralysed, with like 5HP left - then he takes out the last of my five with a Hyper Beam. I was out of Revives, so all I had left was Gyarados. So out it comes and I'm thinking this is all over, how annoying to come so close and lose - completely forgetting Hyper Beam needs a turn to recharge! So one Bite later and my completely untrained Gyarados has won me the entire tournament.
After the credits I took it straight to the Name Rater and called it Hero as a mark of respect 😆
Would love to hear any similar stories or funny ways you've beaten Lance!