Enable is set for a stern test on her eagerly-awaited return to the track on Sunday, with Ghaiyyath one of her key rivals in an eight-strong entry for the Coral-Eclipse at Sandown.
The dual Prix de l'Arc de Triomphe winner is set to reappear for the first time since she lost her 12-race unbeaten sequence when runner-up to Waldgeist in pursuit of her hat-trick in Paris last October.
John Gosden's brilliant mare will be defending her Sandown crown, having begun her campaign last summer with an odds-on victory in the Eclipse.
At six, she is due to face a tough challenger in Charlie Appleby's Ghaiyyath - a year her junior and a dual winner since finishing only 10th of 12 at ParisLongchamp last October.
Ghaiyyath made virtually all for emphatic victories in the Dubai Millennium Stakes at Meydan and then the re-routed Group One Coronation Cup at Newmarket earlier this month.
Among his and Enable's potential opponents at Sandown are the mare's stablemate Lord North, an impressive winner of the Prince of Wales's Stakes at Royal Ascot.
Adding further intrigue is the Japanese mare Deirdre, winner of the Nassau Stakes last season.
Aidan O'Brien's chief hope is last year's Juddmonte International winner Japan, who was below-par at Ascot on his reappearance, and he may be joined by stablemate Magic Wand.
Regal Reality and Bangkok complete the field.