Does the fact that a woman is able to compete with men in auto racing prevent them...

[hippohippo]

...from being real sports? My friend and I got into an argument over whether or not Indycar and NASCAR are real sports. I believe that because it is still a competition of skill, that they are in fact sports. I immediately found flaws in all of his arguments, but then he claimed that because women like Danica Patrick are able to compete on basically equal levels as men in auto racing it can't be a legitimate sport.

Is his argument valid?