Last year's Prix de l'Arc de Triomphe heroine Enable will go head-to-head with King George runner-up Crystal Ocean at Kempton on Saturday.
The John Gosden-trained Enable has not raced this term after suffering a setback in May and now faces a tough task upon her return in the 188Bet September Stakes.
While Enable ended 2017 with five Group One wins, she will have to compete against Michael Stoute's Crystal Ocean in a top-class clash on the all-weather.
Crystal Ocean finished second in last year's St Leger and has won three times this season, including the Hardwicke Stakes at Royal Ascot, before finding only stablemate Poet's Word too good in the King George.
He is rated 1lb superior to Enable, but will have to concede 8lb due to the conditions of the 12-furlong Group Three.
Gosden has a second string to his bow in Ebor second Weekender, who, like Enable, is owned by Khalid Abdullah.
Roger Charlton's Cribbs Causeway and the Richard Hannon-trained Peak Princess complete the five-strong field.