The same thing happened to me but I was the passenger and there was a kid in an S2000 picking on my friend's Civic. I told the guy to wait for me and went and got my car and got him pretty good, he had some work done to the car too. Luckly I had my camera with me and my friend taped it, here are the videos: (this is back when I had a 98 GTP)
YouTube - S2000 vs GTP - 1st race
YouTube - S2000 vs GTP