Britain's Zara Phillips competes in the Eventing Individual Dressage equestrian event at the London 2012 Olympic Games in Greenwich Park, July 29, 2012.[Photo/Agencies]

London - Zara Phillips, granddaughter of Queen Elizabeth II, wows some royals and the home crowd during her Olympic equestrian debut, pronouncing it "an amazing feeling" to compete in the London Olympics and earning a respectable score in the eventing dressage competition despite a slight mistake.

Zara Phillips rode early in the second competition day, just as the wind was picking up but before threatening skies gave way to rain.

She rode a solid test, looking calm despite a couple of bobbles from her horse, High Kingdom, and ended in 24th.

Her grandfather the Duke of Edinburgh, Olympian mother Princess Anne and rugby-playing husband Mike Tindall were on hand to watch her.

When accosted by an unusually large media pack after her ride, Phillips smilingly refused to discuss her royal grandmother, saying today was "about the sport".

"I had a couple of mistakes but overall I was pleased with how he dealt with everything. But he still has a lot to learn," she said. "Cross-country is our strongest phase so we hope we can improve our score."

Britain's Princess Anne (2nd L) and Prince Philip (2nd R) laugh as they watch Princess Anne's daughter Zara Phillips compete in the Eventing Individual Dressage equestrian event at the London 2012 Olympic Games in Greenwich Park, July 29, 2012.[Photo/Agencies]