(CNN)Race favorite Justify, ridden by Mike Smith, won the 144th Kentucky Derby on a sloppy track at Louisville's Churchill Downs on Saturday.
Favorite Justify wins Kentucky Derby on wettest race day
Justify is trained by Bob Baffert, who now has five Derby wins.
Baffert said he knew he had a "really, really special horse" after Justify won a maiden race California's Santa Anita Park in February. Still, he said, he fretted most of Saturday because of the terrible weather.
That is, until Justify took the lead in the final turn.
"I was just in awe of the performance," he said. "That's the best Kentucky Derby-winning performance that I brought up here. "
Good Magic finished second, just ahead of Audible. The winning time was 2:04.20.
Justify, the 5-2 favorite, became the first Derby winner in 136 years that did not race as a 2-year-old. The chestnut colt has won all four starts as a 3-year-old.
The race was the wettest in the event's history, as more than 3 inches of rain fell Saturday.
Justify broke from the No. 7 post well, ran to the front with Promises Fulfilled and pulled away just as the horses passed the 3/4-mile marker in the 1-1/4 mile race.
Smith, who won the Derby on Giacomo in 2005, said the victory was due to the horse.
"My job was just to get him out of there," he said. "I just basically stayed out the way."
Smith has more than 5,000 wins as a jockey. But he said: "I've never been on a 3-year-old like this."
Mendelssohn, the European-trained colt that was a 6-1 favorite, struggled and finished last in the 20-horse field.
The favorite has won the Kentucky Derby for six consecutive years, the longest streak in the race's history.
The next race in the Triple Crown series is May 19 -- the Preakness Stakes at Pimlico Race Course in Baltimore. The Belmont Stakes in Elmont, New York, is June 9 at Belmont Park.