Forever Together shed her maiden tag with a stunning victory in the Investec Oaks at Epsom.
Trained by Aidan O'Brien and ridden by his son, Donnacha, Forever Together was a 7-1 chance having failed to win any of her three previous starts, most recently chasing home stablemate Magic Wand in the Cheshire Oaks.
O'Brien fielded five of the nine runners in all and it was Bye Bye Baby who cut out the early running.
She began to falter early in the home straight and was swiftly passed by Forever Together and the 5-2 favourite Wild Illusion.
However, it was soon clear Forever Together had far more to give and she came home four and a half lengths clear of the market leader.
Bye Bye Baby boxed on bravely for third, with Magic Wand fourth.
Donnacha O'Brien - who won the 2000 Guineas for his father aboard Saxon Warrior - told ITV Racing: "She was very impressive. I got a beautiful trip through, I followed Ryan (Moore, on Magic Wand) and he gave me a bit of company until I got to the rail.
"She's very genuine and galloped right out to the line, she's a proper staying filly."
He added: "I should have been closer at Chester, we just ran into a bit of trouble. About a week ago I thought she had a right good chance and then the rain came so I was a bit worried, but she's handled it really well.
"To be honest, I didn't expect her to do it. I had the perfect position the whole way. It all went perfect.
"When you're riding one of his (his father's) you have a chance, he's an absolutely genius. He can do things with horses I don't understand, he brings out massive improvement and I don't know how he does it."
Aidan O'Brien said: "It's incredible, I'm so delighted for everyone, so thankful to Michael (Tabor), John (Magnier) and Derrick (Smith), it's brilliant for everyone.
"She caught the eye at Chester, she's a staying filly and got the trip very well.
"She's obviously by Galileo and it's unbelievable. Donnacha gave her an unbelievable ride, it's incredible.
"We're all so happy and grateful."
Trainer Charlie Appleby said of Wild Illusion: "She ran a very creditable race. The winner looks to have outstayed us.
"She got a good run into it, but I thought the leader had skipped clear. She has just been outstayed, it's as simple as that.
"When William (Buick) made his move I thought she was going to go through with it. William said she was not comfortable coming down the hill. She came there to win her race, but the winner has outstayed us and was the better horse on the day.
"I don't think we've lost too much in defeat."