Parent's Prayer led her rivals a merry dance in the Cazoo-sponsored Princess Elizabeth Stakes at Epsom.
A dual winner during her debut season as a three-year-old last term, Archie Watson's filly had run two sound races in defeat so far this year - finishing second in the Park Express Stakes in Ireland and fourth in the Chartwell Fillies' Stakes at Lingfield.
Ridden by champion jockey Oisin Murphy for the first time, the daughter of Kingman was sent straight to the lead and appeared to have matters under control throughout.
If anything the 4-1 winner extended her lead racing inside the final two furlongs and passed the post with just over two lengths in hand over Nazuna, with 7-4 favourite Statement only third.
Murphy said: "She's a lovely filly - a great, athletic type. She handled the track really well.
"Her owner is watching at home in Saudi Arabia and he will be over the moon. He jumped in the Olympics in 2012 in London and he knows horses very well, so I'm pleased he's got a top-class filly.
"We weren't absolutely sure as to how we were going to ride her - it was an open plan. But she jumped very well and she was very relaxed going to post, so once she pricked her ears in the race and was in a good rhythm, she was always going to run well."