The royal box erupted with wild cheers as the Queen’s colt raced towards the finish line.
But despite the presence of many of her grandchildren as talismans, the monarch was out of luck at the Investec Epsom Derby, as her horse, Carlton House, came in third.
But the 120,000-strong crowd hadn't come merely for the fashion. All eyes were on the Royal Box, which was decorated in the Queen’s racing colours of red, purple and gold in anticipation of the result.
The suspense inside was palpable. Sophie Wessex covered her eyes with her hands as Prince Harry punched the air and cheered wildly for the royal colt.
The Queen did not appear on the balcony during the race, preferring to watch it on television inside. One race official said she was "just too tense".
It was difficult to say who looked more excited between Princess Eugenie and her sister Beatrice, who was seen shouting at the top of her voice, hands balled up with tension.
Bea had dressed in a ladylike floral shift dress paired with a matching white oversized flower headpiece, further cementing her newfound sartorial clout.
Earlier in the day, Kate had been seen cheering on Sohraab, a horse in which her parents, as members of a racing syndicate, have a share.
And her mother Carole Middleton was also spotted watching the races from the stand.