LOUISVILLE, Ky. — Curlin looked as good in his return to the United States as he did when he left.

The reigning horse of the year won for the fifth straight time today, easily taking the Stephen Foster Handicap in his first race on American soil in more than seven months.

"A stepping stone of everybody jockey's dream, and he fulfilled a lot for me — taking me across the world and back," jockey Robby Albarado said.

In doing so, the 4-year-old colt, coming off a victory in the world's richest race — the $6 million Dubai World Cup in March, got redemption on one of the only racetracks that has given him any trouble. He finished third in his previous trip to Churchill Downs, last year's Kentucky Derby.

But this was no Derby field. In this race, Curlin was in a class all by himself. He has won nine times in 12 lifetime starts and never finished worse than third.

Starting from the rail, the 2-5 favorite waited under Albarado until after the second turn, then clicked into another gear to coast to victory by more than four lengths.

"Great, phenomenal!" Albarado said. "He's an amazing horse. Again with his routine brilliance, he is in textbook form. He's showing that he is a superstar."

Einstein, the 6-1 second choice coming off a win in the Grade I Woodford Reserve Turf Classic on the Derby undercard, took second by a nose over Barcola, who had led most of the race.

"It's a victory for us, I think," said Einstein's trainer, Helen Pitts. "It really is. I thought we'd been nosed out for second, but I was still tickled to death with the way he finished."

Curlin paid $2.80, $2.20 and $2.10. Einstein returned $3.80 and $3.20, and Barcol paid $6 to show.

Curlin won $589,000 of the $1 million purse Churchill guaranteed provided at least one Grade I stakes winner competed in the race. His lifetime earnings are now $9.4 million, third behind only Cigar ($10 million) and Skip Away ($9.6 million).

It was the second time ever that a horse has won the Dubai World Cup and Stephen Foster in the same year. Street Cry, the sire of Street Sense who beat Curlin in last year's Kentucky Derby, also accomplished the feat in 2002.

"It's such an honor to be involved with this horse," Curlin's trainer, Steve Asmussen, said. "He is such a beautiful animal."

Asmussen said he is pondering the possibility that Curlin's next race could be on turf, but no decisions have been made.

Curlin's dominating win came despite a handicap system in which he was forced to carry 128 pounds — at least 10 more than any other horse in the race. Asmussen had complained before the race that racing officials had asked the horse to carry too much.

"Kentucky horsemen appreciate this horse," said Curlin's co-owner, Jess Jackson. "What he stands for is a classic champion, and we'll see how great he is because he is not fully defined."

By starting from post No. 1, Curlin was stuck between horses much of the early going. But when it became a three-horse race, last year's Preakness Stakes winner was in his element.

The rail wasn't nearly so kind in the Belmont for this year's Derby and Preakness winner, Big Brown, who was pulled up by jockey Kent Desormeaux in that race and finished last. In the Stephen Foster, Desormeaux saddled Sam P., who finished eighth in the 10-horse field.

While Curlin was the closely watched Asmussen horse Saturday, stablemate Pyro also ended up in the winner's circle during the undercard Grade III Northern Dancer Stakes.

Pyro, who finished eighth in the Kentucky Derby last month, won the race that featured a trio of Derby also-rans, including Visionaire, who finished third Saturday, and even-money favorite Recapturetheglory, who was fourth. My Pal Charlie finished second.

Pyro paid $5.60, $3.60 and $2.60. My Pal Charlie returned $6.60 and $3.60. Visionaire paid $3.20 to show.