Kate Middleton at the Olympics Supporting Zara Phillips

British royals Kate Middleton and her husband Prince William have attended the 2012 Summer Olympics equestrian cross-country phase on Monday.

The London Games event took place at Greenwich Park where the royal couple displayed support for Zara Phillips, Queen Elizabeth II's granddaughter, as she competed in the Eventing Individual Dressage event.

The Duke and Duchess of Cambridge donned casual clothing, with Kate in a navy blazer over a white shirt and William in a navy collared shirt. Supporting his cousin, William clapped alongside his wife during Phillips' first Olympic equestrian eventing competition.

Phillips, who made her Olympic debut in the dressage Sunday, rode High Kingdom in the dangerous equestrian cross-country phase at the 2012 Summer Olympics. She finished clean and well under the pace of time while her family and thousands of other fans cheered her on.

"The crowd was unbelievable," exclaimed Phillips after she had completed the course, according to ESPN. "I hope I didn't take any heads off on the way cutting corners."

Also in the stands with the Duke and Duchess of Cambridge was Camilla, Duchess of Cornwall, the wife of Prince Charles, Prince Harry, and many other members of the royal family. Phillips' mother, Princess Anne, sat beside Prince Philip in the stands at Greenwich Park Monday, while Princess Beatrice and Princess Eugenie, the daughters of Prince Andrew, also attended.

As part of a three-discipline eventing competition, the cross-country portion of the Olympic event is designed to test the horse and its rider for endurance and skill and contains razor-sharp turns, drops, and difficult combination jumps.

Phillips said she finished in nine minutes, 55.11 seconds- far below the 10-minute, 3-second time limit.

The former world and European eventing champion is 14th in line to the British throne. Phillips, 31, is married to rugby player Mike Tindall, whom she was introduced to by her cousin, Prince Harry.