LONDON -- Zara Phillips did her royal family proud.
The granddaughter of Queen Elizabeth II wowed the home crowd and a few relatives in her Olympic equestrian debut Sunday, riding her appropriately named horse, High Kingdom, to a respectable finish in the eventing dressage competition.
The 31-year-old Phillips registered a slight mistake and earned 46.1 penalty points at Greenwich Park, placing her 24th out of 74 riders with two disciplines to go.
Her grandfather, Prince Philip, the Duke of Edinburgh, and her mother, Princess Anne, were in the VIP seats as Phillips put High Kingdom through the paces of a standard dressage test to demonstrate the horse's obedience.
Cheers and applause broke out as Phillips, 14th in line to the British throne, rode into the stadium, and cheers erupted again when she finished. Anne, wearing a bright red canvas hat, applauded politely.
"To be here at home is an amazing feeling, and you just want to try and do your best for the team," Phillips said.
Three other British riders did better, and their scores contributed to Britain's third-place finish at the end of dressage.
Germany was in the lead with 119 penalty points, followed by Australia with 122.1 and Britain with 127. The United States was seventh with 138.8. As in golf, the low score wins.
The competition continues Monday with the dangerous and unpredictable cross-country portion, followed by show jumping Tuesday.
High Kingdom made a mistake toward the beginning of the canter in the first of a maneuver known as the flying change. The horse is supposed to change the sequence of its steps, but High Kingdom didn't respond immediately to Phillips' cues.
"It was disappointing about his first change, but his other ones were really good," she said. "But he coped with all the crowd and is only getting better."
Phillips, a former world and European eventing champion, performed early under a sunny sky. Later, storm clouds and lightning moved in, forcing a brief suspension of competition and drawing complaints from some riders who had competed through the rain.
Phillips said High Kingdom's mistake had nothing to do with the enthusiasm from the stands – a rousing welcome that prompted the announcer to remind the audience to keep applause to a minimum until the test was finished.
"He's very chilled," she said of her bay gelding. "That was nothing to do with the crowd. It was just inexperience and getting stronger, and he's getting stronger all the time."
She said she was looking forward to Monday's cross-country event, which she said was High Kingdom's strongest because he is a good jumper. The 28-obstacle course over 3.5 miles through the bucolic Greenwich Park is hilly with several tight turns.
"He's quite quick and easy to turn, so hopefully it'll be good," Phillips said. "I think he wants to get out there now. He's a bit bored of dressage."
In an indication of the respect the royal granddaughter has in the equestrian world, Phillips was warmly greeted after she competed by Mark Todd and Andrew Nicholson of New Zealand.
At the end of the dressage portion, Japan's Yoshiaki Oiwa led the individual competition on Noonday de Conde with 38.1, Stefano Brecciaroli of Italy on Apollo WD Wendi Kurt Hoev was in second place with 38.5, and Todd on Campino had 39.1.
But in eventing, anything goes, and team leader Germany said Monday's cross-country could shake both the team and individual standings around.
"It's a three-day competition, and not a dressage show," said German team coach Hans Melzer. "I think tomorrow is a new competition, and everyone starts with zero."
Phillips' grandmother stole the show during the opening ceremony Friday, appearing opposite Daniel Craig's James Bond in a short film, then formally opening the games. She visited with fawning British Olympians in the athletes village on Saturday.
The gold-medal question was whether the queen would attend Phillips' brief four-minute test. Instead, her husband represented the monarchy. Princes William and Harry and William's wife, Kate, are expected to appear over the next two days.
Equestrian is being held in a regal venue: Greenwich Park dates from 1433 and is the oldest royal park in London. The main equestrian arena sits in front of Queen's House, a 17th-century building designed as a summer palace for Queen Anne of Denmark, the wife of James I.
Horses are big in the royal family. The queen is an accomplished and enthusiastic equestrian and at 86 still rides often – without a helmet.
Princess Anne is not only president of the British Olympic committee but a member of the International Olympic Committee and a former Olympian in equestrian eventing herself.
She competed at the 1976 Montreal Olympics, but her horse fell going over a jump during the cross-country event. Phillips father, Capt. Mark Phillips, fared better, winning team gold at Munich in 1972 and silver in Seoul 16 years later.
Mark Phillips is now a top coach of the U.S. equestrian team and sat a few seats away from Anne, his ex-wife, to watch his daughter compete. Phillips' brother Peter was also in the stands.
In a recent BBC interview, Anne acknowledged the pressure British athletes were under competing on home turf.
"I'd hate to be doing it now – that's all I can tell you!" she said.
But her 31-year-old daughter played down the pressure, telling reporters earlier in the week she would have no trouble competing with other royals in the stands.
"They're my family. It's not weird," she quipped.
Phillips had qualified for the 2008 Beijing Games but had to pull out after her horse, Toytown, got was injured. British equestrian officials have stressed that Phillips is on the team because she's an excellent athlete, not because she's royal.
Phillips and brother Peter have low profiles in the royal family. They hold no royal titles, unique among the queen's eight grandchildren, after their mother turned down the monarch's offer of honors.
Nevertheless, both are very much part of the royal family. The queen and Prince Philip were honored guests at her wedding last year to international rugby star Mike Tindall, who has been photographed playfully wrestling William and Harry until they begged for mercy.
Tindall escorted Phillips to the stable after her ride, and even took a picture for an Olympic technician who wanted a photograph taken with his wife.
The seventh-place U.S. team, heading into Monday's cross-country, faced a double whammy – a disappointing dressage result and a poor draw.
On Sunday, Phillip Dutton of West Grove, Pa., earned 44.3 and 19th place out of 74 riders on Mystery Whisper, while Will Coleman of Gordonsville, Va., scored 46.3 on Twizzel and sits 26th, adding to the scores their teammates earned Saturday.
The Americans must also send their riders out first in cross-country. They will need gallop all out without knowing the standings of the other riders, who can ride more conservatively knowing precisely what kind of score they need.
The time to meet is 10 minutes, 3 seconds. Penalties for exceeding the optimum time will likely separate the eventual winners from the rest of the pack.
Margaret Freeman contributed to this report.