The prolific Nazeef successfully graduated to Group One level with a thrilling victory in the Tattersalls Falmouth Stakes at Newmarket.
Third on her July Course debut in June of last year, John Gosden's filly had since won each of her five starts, including the Duke of Cambridge Stakes at Royal Ascot last month.
Stepping up the top table for the first time, the Hamdan Al Maktoum-owned Nazeef was a 9-2 shot in the hands of Jim Crowley, with her stablemate Terebellum the 5-6 favourite following her narrow defeat to Circus Maximus in the Queen Anne.
The latter set out to make all the running under Frankie Dettori, but both Nazeef and Billesdon Brook reeled her in as the post loomed, with the former emerging triumphant by a neck.
Crowley said: "The only pace in the race really was Frankie's filly (Terebellum) - she'd won over 10 furlongs and all the others looked like they were going to take a lead. I had a great position in a small field and managed to get a bit of cover.
"She's as tough as nails and she's improved with every run. That's six races in a row she's won now - she's climbed her way up the ladder. She's a really gorgeous looking filly as well, with plenty of size and scope about her.
"She is so versatile and would probably stay a bit further. I actually thought at Ascot she needed every yard of the mile to win and you could argue it was the same today.
"I'm not sure what the plan is - that's up to connections. If they wanted to stick at a mile with her they could, or if they wanted to step up to 10 furlongs, I think she'd be competitive in a Nassau Stakes or something.
"Wherever she goes, it's just a pleasure to ride her."