Watched by her royal relatives, who were out in force, including the Duke and Duchess of Cambridge, Zara Phillips won a silver Olympic medal as part of Team GB's equestrian squad.
And her mother Princess Anne, herself a former Olympian, was due to present the coveted prize.
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Having ridden in the 1976 Montreal Games, no one is better placed than the Princess Royal to understand the challenges that Zara faced.
During a nervewracking final day of competition, the Queen's family attempted to stay upbeat despite the anxiety they must have been feeling.
Kate, flanked by Princes William and Harry and wearing the navy £500 Smythson blazer that first appeared on her North American trip, smiled and joked.
Meanwhile, the Duchess of Cornwall chatted with her sister-in-law Anne.
Behind them were Princesses Beatrice and Eugenie, the daughters of the Duke of York.
Their girl entered the arena at Greenwich Park, south east London on mount High Kingdom to a massive round of applause from the crowd.
Cheers gave way to silence as Zara, the 2006 world champion, tackled the course. The Queen's granddaughter clipped a fence and incurred a time fault, meaning she went over the allocated 83 seconds.
But all in all it was a solid performance, especially given her recovery from that initial mistake – and the courageous display earned her another roar of approbation from spectators.
"I just had to get on with it [after the second fence went down]. Unfortunately that happens," she said.
Things eventually fell into place for the eventing heroes when fellow Olympians Mary King and Tina Cook treated the crowds to flawless performances – and galloped off with silver.
Germany took top spot, with New Zealand snapping at Britain's heels in third place.
The competition was set to continue on Tuesday with the individual stage in which the top 45 riders, including Zara, could take part.
No wonder the royal laughed when asked if she'd had time to celebrate the first anniversary of her wedding to Mike Tindall on July 30. Perhaps, the rugby ace will find time to spoil Olympic heroine.
Guide to Olympic Equestrian
Zara and her teammates are flying the flag for Britain in Eventing – an equestrian discipline that combines dressage, cross country and show jumping.
On the third and final day of the competition, scores from all three activities are collated and medals are awarded.
On day one, competitors took part in a dressage test. Dressage is the French term for 'training' in which riders score points based on their ability to guide the horse through a series of graceful movements.
Next, came the cross country event, where riders had to complete a tough 5.7km course within an allocated time limit.
Jumping mistakes or exceeding the time limit result in penalty points being added to the previous day's dressage score.
Finally, the event concludes with showjumping where riders must clear the course against the clock and without knocking down any fences.