Stuck On Lakeshore Online Racers League, Game Won't Let Me Progress

So after multiple attempts, I beat Rudiger's challenge or whatever as part of the Racers League.  However, even though I beat him fair and square, the game still says I need to find him on the map and challenge him.  Did I do something wrong?  Is there some secret parameter I didn't meet?  Has anyone else ran into this issue?  Whatever the answer is, I am at my wit's end and I need your help.  Thank you very much for your time, and I hope to hear from you very soon.