Queen Elizabeth II made history in the horseracing circuit when she became the first-ever British sovereign to win the Gold Cup at the Ascot Race.

The Queen was very excited as the Royal Ascot progressed on its third day, after her horse, Estimate, frolicked home to grab the highly-coveted Gold Cup. In Ascot's 207-year history, no other sovereign has grabbed the top award.

The dark bay thoroughbred filly was the 7/2 favorite and won by a length, reports The Mail Online.

Estimate's win caused the Queen's grand daughters, Princesses Beatrice and Eugenie, to leap with joy at the royal box. Meanwhile, the 87-year-old monarch contented herself by clapping her hands, while the horse was doing her best to reach the finish line first.

Estimate, who won the Queen's vase last year, was a crowd favourite. And as the Gold Cup was nearing its end, the horse, who ran for over 4,000 meters, managed to outpace the rest of the pack, and succeeded in overtaking the front runners until she reached the finish line.

Estimate's success cheered the Queen, despite the Duke of Edinburgh's absence. The Queen's husband has been at the race regularly, but he missed this year's event as he is still convalescing at Windsor Castle after undergoing abdominal surgery.

Queen Elizabeth II's grandson, Peter Phillips, explained that horsing racing is her grandma's passion and that Estimate's success made her really happy.

"It's amazing, this is her passion, every year she strives to have winners and to have the big one at Royal Ascot means so much to her and to everyone involved in racing. A win like this is truly, truly special," he said in an interview with Mail Online.

Sheikh Mohammed bin Rashid Al Maktoum, ruler of Dubai and an avid horse-racer, too, approached the Queen to congratulate her.

Queen Elizabeth II was supposed to hand out the winning trophies for the Gold Cup, but since she herself was a winner, his second son, Prince Andrew, Duke of York, decided to step in for her triumphant mother.

The monarch was all-smiles as she proceeded to the parade ring for the awards ceremony, while throwing chit-chats with her jockey Ryan Moore and horse trainer Sir Michael Stoute. Everyone flocked to the stands as they were eager to catch a view of the celebrity horse and her equally celebrated master.

Prime Minister David Cameron immediately sent out a tweet to congratulate the Queen: "Huge congratulations to Her Majesty for Estimate's victory at Royal Ascot - first time ever a reigning monarch's horse has won the Gold Cup."