Just over two minutes later, a winner will emerge and thoroughbred racing will have its newest contender for a Triple Crown. The Preakness follows in two weeks and the Belmont Stakes is June 8. The last horse to sweep all three races was Affirmed in 1978.
Black Onyx was scratched from the race on Friday.
NBC televises the 1¼-mile race from 4 p.m.-7 p.m. The purse is $2,199,800, with $1,439,800 to the winner.
Here's a running account of the event and everything going on around it, with journalists from The Associated Press bringing the flavor and details of everything surrounding the race.
HUMANA DISTAFF: Aubby K, the 7-2 favorite, rallied past Burban to win the $345,600 Humana Distaff for fillies and mares. Edgar Prado guided the 4-year-old through the slop to get up by 1 ½ lengths for her second straight stakes victory.
MORE SLIDING, FEWER CUFFS: The normally rowdy infield crowd at the Kentucky Derby appears well behaved.
As the rain comes down, fans have taken to sliding across water-slickened tarps and muddy stretches in a makeshift slip-and-slide.
Louisville Police Officer Carey Klain said as of mid-afternoon, only two people had been arrested and three cited for ticket scalping.
"So far, so good," Klain said.