Hurricane Run faces a strong challenge from stablemate Shirocco as it bids for a repeat win at the Prix de L'Arc de Triomphe on Sunday.
Hurricane Run, a 4-year-old colt, will start favorite in an eight-horse field at the Longchamp course in Paris' Bois de Boulogne.
Ridden brilliantly by jockey Kieren Fallon a year ago, Hurricane Run's late burst saw him pass Epsom Derby winner Motivator and Westerner.
Owner Michael Tabor feels the colt's natural speed could be threatened by Shirocco which placed fourth last year and will be ridden by Christophe Soumillon and the Japanese-owned Deep Impact.
"I'd like to think he'll beat Shirocco, but an independent observer might think differently," Tabor said. "Then you throw in Deep Impact ... from what we're told he's very, very good."
Soumillon, who has an instinctive understanding of the 2.4-kilometer (1.5-mile) track, is free to ride the 5-year-old Shirocco because Mandesha, owned by Aga Khan's daughter, pulled out.
Paul Harley, the racing manager to owner Baron Georg von Ullman, believes Soumillon could be the difference for Shirocco to beat Hurricane Run, reports AP.
"He knows the horse extremely well and will now what to expect on the day," Harley said.
Hurricane Run, Shirocco, and 2-year-old Rail Link, the Prix Niel winner, are among the entries.
All three are trained by Andre Fabre, the most successful trainer in Arc history. Fabre has won Europe's most prestigious horse race six times: 1987, '92, '94, 97, '98, and last year.