The 23-year-old Frost was roared home by an ecstatic crowd to win the Ryanair Chase onboard the Paul Nicholls-trained Frodon to secure her place in the record books.
The pair’s thrilling victory delighted Frost’s friends and family in the winner’s enclosure.
“He’s Pegasus! He’s got wings,” said an overjoyed Frost to ITV Racing at the finish line.
“Most horses would quit, but he grabbed me by the hands and said, ‘don’t you dare give up, don’t you dare not send me into the last – I want this more than you, now come on, where are you?’
“Just look at what he’s done there – deny that he just loves racing. He’s unbelievable. I love you.”
Frost added: “He just made the dream come true, it’s just incredible. He will deserve every single high five, pat and carrot.”
READ: A day in the life of Paul Nicholls’ racing yard
The pair was treated to a thunderous reception as they returned to the parade ring where Frost’s family were waiting to congratulate the history maker.
“I’m just so proud of her, that was an amazing ride,” said Frost’s mum in front of her visibly emotional daughter.
Many on social media are calling Frost’s win the best moment of the showpiece jump racing festival so far and Frodon’s trainer Nicholls agreed.
“One of the best days ever,” said the 10-time champion trainer, who has won the Cheltenham Gold Cup four times with legendary horses such as Kauto Star and Denman.
In the following race, Paisley Park ran home winner of the Stayers’ Hurdle to whip the crowd into a further frenzy.
The horse is owned by Andrew Gemmell — who was born blind — and who was crying and dancing from the stands as someone narrated the race to him.
“Wonderful. It’s fantastic. I’m aware we’re on air so I won’t say what I want!” he told BBC Radio 5 live.
“I can’t believe it’s happened. I’m in tears. Wow. I couldn’t see the race but that roar is incredible!”