tl;dr at bottom
In high school I happened to get the flu right before our local track championships. They were a requirement to go onto regionals, so I ran anyway.
I ended up coming second in both the steeple and the 3km to this guy who had no business beating me, but hey, I was sick and had no reason to drop the hammer (top 5 move on). Anyway, long story short, after the second race I heard him talking to some of his buddies and he was acting all cocky and saying he was just going to sit behind me and kick at the end like both the other races and that he basically had it in the bag. I didn't like that.
By the time the 1500m started all that was going through my head were his words and how much I just wanted to embarrass him in the race. So, this was when I was a pretty slow runner .. pb was something like 4:35 or something. I started the race and said, going to sit and kick? Try and match this. Dropped the hammer and went 62 seconds through the opening lap. Both of us died, but I managed to hold on for the win by a 15 second margin in 4:25.
Back then, that was like running the world record. No one went under 4:30 in the 1500. No one. Needless to say, the 1500m became my favorite race from that day forward.
tl;dr Guy said he was going to sit and kick to beat me. I dropped the hammer and opened 11 seconds faster than pb pace and held on for the win.
Also, some team mate of mine cut me off in a workout one time when it was my turn to pace. Not only did he cut me off, but he then slowed down. Needless to say I dropped the hammer with 200 to go and put 50m between us. Team mates applauded because he had been racing workouts all year.