LOUISVILLE, Ky. (AP) — Mike Smith’s clean white and green silks were the most obvious indicator of how well the Kentucky Derby went for the Hall of Fame jockey aboard Justify.

Staying nearly spotless wasn’t easy in pelting rain and on a muddy, crowded track. But Smith got Justify near the lead at the start and left the other horses to deal with the muck as the pair splashed to a 2½-length victory Saturday in the 144th Run for the Roses.

It was the second Derby victory for Smith, who helped Justify improve to 4-0 and become the first horse since Apollo in 1882 to win without racing as a 2-year-old.

The 52-year-old Smith, known as “Big Money Mike” for his performance in big races, is the second-oldest Derby winner behind Bill Shoemaker, who rode Ferdinand to victory in 1986 at age 54.

Given his conditioning and seamless trip aboard Justify, Smith seems capable of surpassing that mark.

Asked about the secret to his success, Smith said: “Just keeping riding horses like this and that’ll keep you around a long time. You don’t have to work a whole lot; they do all the work for you.”

Perhaps, but it’s hard to imagine another jockey getting so much out of a rookie on the sport’s biggest stage.

Smith, whose first Derby win came aboard Giacomo in 2005, is known as being one of the sport’s healthiest riders and a keen tactician. That helps explain why trainer Bob Baffert chose Smith to ride Justify after breaking his maiden beneath Drayden Van Dyke, and why he appeared so calm all week.

The rain and track made Baffert nervous, albeit only briefly, as Justify and Smith ran another impressive race.

“When he got away clean then I thought we had a chance,” said Baffert, who earned his fifth Derby win and first since American Pharoah’s 2015 victory on the way to the Triple Crown. “We had to get away. Then Mike took his time.”

Justify came into the Derby off a three-length win in the Santa Anita Derby and even had a March win in the mud at the California track. Despite concerns about the so-called Apollo Curse continuing, he went off as the 5-2 favorite from the No. 7 post at Churchill Downs.

Smith made sure the horse quickly delivered on the expectations.

He found a hole right away for Justify out of the gate and kept the horse to the outside alongside Promises Fulfilled through the backstretch. He made his move in the far turn and steadily pulled away for his most significant win.

“He’s got that ‘it’ factor,” Smith said. “He is so above average, he’s got unbelievable talent and he’s got a mind to go with it. He was loving this stuff. He’s so big and talented.”