I had a similar thing happen to me about 20 years ago. I was the “runner” in our high school, and a 10 minute 2-miler and ended up running D3, peaking out just above 15 for the 5000. A friend of mine was a great athlete – best RB on the football team, high scorer on our basketball team, and a good lacrosse player. He played lacrosse D3. Could probably beat me at any sport or game imaginable.
A couple of years out of college he started running to stay in shape and started doing some road races. My high school buddies and I were out one night and they started to say this kid could beat me in a 10K. They literally were taking bets with each other, with most people betting on this kid. My best friend asked me what he should do and I told him to bet all the money he could on me. I could run about 32 minutes at the time.
So, the next weekend everyone shows up to watch us run. The gun goes off, he is alongside me for about 150 yards, and says, “holy crap, are you going this fast the whole way?” and drops back. I ran about 33 and he ran about 40 minutes.
But, here is why I am posting. You are going to WASTE this kid, no question, even if he isn’t lying. But, what is going to happen is he will quit early on you and that isn’t any fun. Instead, your goal should be not just to win, but to inflict as much pain on him as possible. Sit on him, get alongside him every once in awhile to push the pace and not give him a break. But, don’t take off until at least a lap to go. Your goal is to make him puke, not just to beat him.
It was completely unsatisfying the way I took this kid on. Learn from your elders…