Ever happened before?

[_ed_]

Today here in NZ there were two horses entered in the same race (I agree that's hardly unusual, but let me finish!):

Da Celtic Tiger 7yo Gelding Victory Dance - Rue
I'm Nobody's Child 4yo Gelding Da Celtic Tiger - Rot Stirne

Apparently Da Celtic Tiger, as a 2yo colt, jumped a fence and got in with the mares! He was gelded immediately afterwards.

Da Celtic Tiger was unfortunately scratched on the morning of the race, but has a horse ever been entered in the same race as his/her sire before?

Yes, this was the most interesting thing that happened in racing here today. Gotta love winter racing.