Lady Bowthorpe provided jockey Kieran Shoemark with his first Group One success - and trainer William Jarvis his first since 1994 - as she won the Qatar Nassau Stakes at Goodwood.
Shoemark held Lady Bowthorpe up in the early stages as Aidan O'Brien's contenders Joan Of Arc and Empress Josephine made the early pace.
Joan Of Arc still led into the straight, with eventual runner-up Zeyaadah in her slipstream. But Shoemark made ground to challenge more than a furlong out and then surge clear for victory by a length and a half at 100-30.
Shoemark told ITV Racing: "I'm pretty speechless. This means so much, not just for me but for (owner) Emma (Banks) and William Jarvis too."
Lady Bowthorpe was striking at the top level for the first time, following her luckless defeat in this month's Falmouth Stakes at Newmarket.
Shoemark added: "She was unlucky in the Falmouth. I'm delighted for them all, and they'll be able to celebrate it tonight. She's an amazing filly.
"She deserves it - she's done nothing but improve with age and she's a credit to her owner Emma, who fills me with absolute confidence.
"I know it was her first run over 10 furlongs, but she'd been finishing over a mile really well, and I wasn't concerned about that."