LOUISVILLE, Ky. — Reigning Horse of the Year Curlin worked seven furlongs over the turf at Churchill Downs today, a first step to a possible run in the Arc de Triomphe at Longchamp on Oct. 5.

The 4-year-old colt, trying to master the turf the way he has the dirt, covered the distance in 1:31.20. Trainer Steve Asmussen called the work perfect.

Curlin, the winner of the 2007 Preakness and Breeders' Cup Classic, is coming off an easy victory in the Stephen Foster Handicap on June 14 at Churchill — his first start since winning the Dubai World Cup in March.

Stonestreet Stables owner Jess Jackson has decided to move Curlin to the turf to prove that he's the best thoroughbred in the world. The Arc is run on turf.

Curlin is expected to race on the turf in either New York or Chicago on July 12.