Well you can try this, though I have no idea if it will work (I'm on PC, not sure if this was a bug, if there is a difference between platform versions, etc.) I wanted to scout out the route before racing him since he beat me the first time (I wasn't even expecting something to happen when I ran past him so I was caught off guard) so I left the screen, returned, and jumped over the rope that triggers him to run. I went all through the course to the end, and walked through the rope there (not really thinking about it but just definitely know that I did because I went to strike the wall to see if it was a breakable spot).
Anyway, I went back to race him for a second time (passed through the first rope), he still got to the end before me, just barely, and.....somehow I was still counted as winning, he fell over dead, and I got his shard.
Might not work, might be some whacked out fluke that occurred that one time, I don't know.