Horse of the Year Curlin worked six furlongs in 1:13.54 on Monday at Nad al Sheba in what assistant trainer Scott Blasi called a “major move” for the $6-million Emirates Airline Dubai World Cup (UAE-G1).

The four-year-old Smart Strike colt completed the workout in 1:13.54 under regular exercise rider Carmen “Carlos” Rosas, going the first furlong (about 200 meters) in :13.40 and the last eighth in :12.19.

“It was exactly what we had in mind,” Blasi said. “I couldn’t be happier with how he went and the rhythm he is in.”

Curlin made his four-year-old debut on February 28 at Nad al Sheba with a 2 1/4-length victory in a listed handicap. Blasi said the colt has matured since his championship season in which he won the Preakness Stakes (G1), Jockey Club Gold Cup Stakes (G1), and Breeders’ Cup Classic Powered by Dodge (G1).

“He’s a very intelligent horse; it’s almost as if he knows what we’re going to do with him,” Blasi said. “When he is on the racetrack with a rider on his back, he’s as professional a racehorse as I’ve ever seen.

“He’s just a stronger, more mature horse. He’s thicker, and he’s put on weight in all the right places. He was a big horse as a three-year-old, but he’s a lot bigger now.”

Curlin most likely will have one more workout before the World Cup, though Blasi said it would not be as demanding as what the colt went through on Monday.

Steve Asmussen trains Curlin for majority owner Jess Jackson’s Stonestreet Stables. Curlin has won seven of ten starts and earned $5,207,800. A Dubai World Cup win would elevate Curlin to third on the all-time list of leadings earners that have run in North America.