I've done it twice. The first time I just finally tried hard enough and after like 20-25 tries I finally got it. I would usually just take my 98 and go on with the game. The second, I was doing a perfect file, where you get everything in the game including the Excalibur 2 (yes, it's possible). That was annoying, because of the time constraint you had to do it in at most three tries or you had to reset, which means you had to go through about 10 minutes of the game again before you got back to the duel. But, I finally got it.