James Fanshawe's Captivator showed determination to short-head the 7-4 favourite Law Of The Range in the Betfred Mobile Sports Snowdrop Fillies' Stakes at Kempton.
Lord Vestey's home-bred had captured some minor black type last season, but appeared an improved mare at five as she landed the Listed prize.
Kieren Fallon pointed Captivator (11-1) through the gaps but faced a sustained challenge from Law Of The Range in the final stages and only just held on.
"We tried her over longer distances last season, but she seems to have become quicker so this mile suited," said Fanshawe.
"She's from a really good family, the dam Cashew has produced horses like Macadamia, and it's great she has stayed in training. I'm going to have to have a think about where she'll go now."
A drop back to a mile brought about a startling turn of fortunes for Nazreef in the Betfred Goals Galore Handicap.
Hughie Morrison's gelding failed at hurdling before winning the Lincoln Trial at Wolverhampton, but had made little impression in last week's Rosebery Handicap at the Sunbury course.
Always in front under Darryll Holland, Nazreef looked surrounded with a furlong remaining, but found another gear to quicken three lengths clear of 100-30 favourite Double Dealer.
Owner Mike Watson said: "We tried him over longer last week, but it didn't really work. He's been a great horse for us. He's best on the Polytrack, but Hughie says he'll go on grass if it's no quicker than good.
"He'd like to run him in the Spring Cup at Newbury, but it might come too fast, so there's races like the Hunt Cup and the London Mile Final here later in the year."