Danica Patrick surprises fan, races Justin Bieber on 'The Ellen DeGeneres Show'

An 11-year-old race car driver received quite a surprise on "The Ellen DeGeneres Show."

Mackenzie Marsh -- who has been racing go-karts since she was just 4-1/2 years old -- got the chance to meet her role model . . . Stewart Haas Racing's Danica Patrick.

Even better? Marsh got the chance to race Patrick, DeGeneres and Justin Bieber in a five-lap shootout.

Check it out.