Pippa Middleton Competes in Triathlon

(GettyImages.com)

While her sister and brother-in-law watched new race, Pippa Middleton actually executed one.

Sis Little Princess Kate participated in the triathlon at Blenheim GE Woodstock, England.

Middleton (# 6642) was all smiles as she crossed the finish line, although we're guessing, a little more tired.

See pictures!