Shumookhi left her rivals trailing in her wake as she made every yard of the running in the Byerley Stud Stakes at Newbury.
Archie Watson’s filly has been set some tough tasks since winning a minor event at Catterick in May.
However, she was not beaten all that far in the Queen Mary Stakes at Royal Ascot and has since been placed at Group Three and Listed level in France.
She was a 15-2 chance for another Listed assignment, in a race better known as the St Hugh’s Stakes, and a flying start saw her take an early lead in the hands of Oisin Murphy.
It was clear racing inside the final two furlongs that her rivals were struggling to bridge the gap and she kept up the revs all the way to the line to score by a fairly impressive three lengths.
Heartwarming was second, three-quarters of a length ahead of Come On Leicester in third.
Willie McCreery’s Irish challenger Lethal Promise was the 5-2 favourite, but finished well beaten in 10th place.
The winning jockey said: “She loved doing that (making the running) and she’s done it well.
“She has clearly stepped up on what she has shown previously. I’m very pleased.
“I think five furlongs is her trip as you need to ride her aggressive and she showed a lot speed there.”
Speaking from France, Watson told Press Association Sport: “I’m delighted. She’s really a really tough and talented filly and she’s been running well in Stakes company.
“You don’t often see Listed races won by that margin, especially over five furlongs.
“She’s in a Group race at Chantilly on September 1, but I’d say it’s probably more likely we’ll wait for the Flying Childers at Doncaster.
“I wouldn’t say we’ll never step her up to six furlongs, but she has plenty of speed and I’m not in a rush to step her up at the moment.”