Frankel's two-year-old half sister Joyeuse has claimed a first stakes, holding on by a neck Listed Fillies' Stakes at Salisbury.
While the already priceless 8-11 favourite was hard-pressed to thwart the charging Dorothy B, connections could point to a variety of mitigating circumstances.
Tackling quick ground and not wearing her usual hood, Joyeuse was also making her first appearance since finishing third behind Kiyoshi and Sandiva in the Albany Stakes at Royal Ascot.
Tom Queally asked Joyeuse to quicken entering the final couple of furlongs (400m) and she reached the front without much trouble but needed the line to arrive as Dorothy B launched a late volley.
She is entered in the Group One Cheveley Park Stakes.
"First of all you have to be very pleased as she's a stakes winner by Oasis Dream and a half-sister to Frankel, and that makes a big difference," Teddy Grimthorpe, racing manager to owner Khalid Abdullah, said.
"She was obviously a bit rusty, she'd been off since Royal Ascot and has grown and developed.
"She probably needed it, but she has still quickened up quite nicely. Obviously the Cheveley Park is there if we want to stay at six furlongs and there's the Rockfel if we want to go to seven.
"I wouldn't have thought the Fillies' Mile would be in our plans."
Coral left Joyeuse unchanged at 12-1 for next year's 1000 Guineas.
Frankel, meanwhile, has begun serving a select group of mare to southern hemisphere time after a fertile first season at stud.