Newmarket: Laurens beats Aidan O'Brien's September to win Fillies' Mile
Laurens won the Fillies' Mile at Newmarket in a photo finish from September to deny record-chasing Aidan O'Brien another top-level victory.
The 10-1 winner, trained by Karl Burke, held on by a nose to give rider PJ McDonald a first Group One win.
"I'm 35 years of age now and the relief when that number got called out was amazing," said ex-jump jockey McDonald.
O'Brien remains on 23 Group One wins in 2017, two short of the record for a calendar year set by Bobby Frankel.
Having won the May Hill Stakes at Doncaster last month, Laurens relished the step up to the highest level and just saw off the fast-finishing runner-up.
Magic Lily was not far away in third, ahead of the O'Brien-trained Magical, who was sent off 15-8 favourite after stablemate Happily was declared a non-runner.
Burke indicated Laurens could be aimed at next year's French Oaks.
BBC horse racing correspondent Cornelius Lysaght
Karl Burke has bounced back stronger than ever after being banned for a year when convicted of breaking rules governing passing on 'inside information'.
Following a period when his wife Elaine held the licence, Burke has become one of the outstanding forces based in the north of England, with a string of successes notably with the filly Quiet Reflection, who runs in the big sprint race on Champions Day at Ascot on 21 October.
PJ McDonald is one of the growing band of jump jockeys - he won the 2007 Scottish Grand National on Hot Weld - to make the successful move to the Flat.