The 14th in line for the British throne has defied the odds, clawing her way to a spot on the British Olympic equestrian team after a strong performance last weekend at Bramham in northeast England.
"She brings a unique ability to deal with pressure," said Jimmy Wofford, a U.S. expert on eventing, the three-part event that Phillips competes in. "I wouldn't want the lifestyle that produced it, but our format these days guarantees a cliffhanger finish ... You have to have Sunday afternoon nerve."
The grueling sport combines the precise balletic movements of dressage, the athletic display of show jumping and the endurance and speed needed for cross country courses.
Only a few weeks ago, the 31-year-old was widely considered to be a long shot to make the strong squad. Britain's sodden spring had led to the cancellation of several big equestrian contests that would have given Olympic decision-makers a chance to see her in action.
But Phillips proved it is a mistake to count her out. She kept charging on, even skipping the huge Thames boat pageant marking her grandmother's Diamond Jubilee — 60 years on the throne — so that she could compete. She and her horse, High Kingdom, just kept getting better, melding as a team, forcing observers to note her consistency and her experience.
Phillips has suffered many disappointments before. She had been selected to compete for the 2008 Beijing Olympics on Toytown, an exceptional horse with whom she seemed to share an uncanny bond. But Toytown got injured only weeks before the games, and since horse and rider compete as a team, Phillips stayed home.
She struggled in the years that followed. But then last fall she came charging back on High Kingdom, a 16.2 hands high (5-foot-6-inch) bay gelding that she describes as "a pretty cool, very relaxed kind of guy."
"It's awesome to be given this opportunity," Phillips said in a statement late Monday. "I am really excited and can't wait to kick on and get him there."
High Kingdom, a thoroughbred, has great speed, an advantage on the London Olympic course at Greenwich, said Lucy Higginson, editor of the equestrian publication, Horse & Hound.
Phillips will be following in the footsteps of her parents — Princess Anne and Capt. Mark Phillips — both of whom competed for Britain in the Olympics.
Princess Anne fell off her horse during the 1976 Montreal Games but still remembered the experience as one of the best in her life. Phillips' father fared better, winning a team gold at Munich in 1972 and silver in Seoul 16 years later. He is now a top coach for the U.S. equestrian team.
Phillips and her older brother, Peter, have very low profiles in the royal family and hold no royal titles — unique among the queen's eight grandchildren — after their mother turned down the monarch's offer of honors.
But Phillips is very much a part of the royal family. The queen and her husband, the Duke of Edinburgh, were honored guests at her wedding last year to international rugby star Mike Tindall, who has been photographed playfully wrestling Princes William and Harry until they begged for mercy.
But can she win gold for Britain? Bookmaker Ladbrokes has made her an odds-on favorite to win.
"Every time Zara goes out now, she looks better, "Wofford said.