Big Brown galloped across the finish-line to a decisive victory Saturday as his nearest competitor, Eight Belles, was struck by injury.

Denis of Cork was third.

The lone filly in the field, Eight Belles broke both of her front ankles in the race. She collapsed on the track and was euthanized.

"There was no possible way to save her," on-call veterinarian Dr. Larry Bramlage said. "She broke both front ankles. That's a bad injury."

The filly's jockey, Gabriel Saez, said Eight Belles began "galloping funny" after they passed the finish-line. He tried to pull her up, but said that's when she collapsed.

"There was no way to save her," trainer Larry Jones said. "She couldn't stand."

Eight Belles became the first horse to be euthanized at a Triple Crown race since Prairie Bayou at the 1993 Belmont. A few weeks earlier, Union City was destroyed at the Preakness.

A spokesman for Churchill Downs said it was not known whether Eight Belles was the first horse to die on the track at the Kentucky Derby.

Eight Belles was trying to become the fourth filly to ever win the Kentucky Derby. Jones and the filly's owner opted to race her in the Derby -- her first race against colts -- instead of the Kentucky Oaks.

Big Brown, the pre-race favorite, showed experience didn't matter Saturday. After racing in just three events before the Derby, the colt used a late-race charge to surge into the lead of the 1 1/4-mile race before winning by almost five lengths.

In doing so, Big Brown, who was ridden by Kent Desormeaux, became the first horse since Clyde Van Dusen in 1929 to win the Kentucky Derby from the No. 20 gate.

Big Brown, who has now won four races, was the seventh undefeated Derby winner. The last unbeaten victor was Barbaro, who won the Kentucky Derby in 2006. Barbaro broke down at the Preakness Stakes and was euthanized months later.

Big Brown will now prepare for the Preakness Stakes, the second stop on the Triple Crown tour. He will attempt to become the first horse since Affirmed in 1978 to win the Kentucky Derby, Preakness Stakes and the Belmont Stakes.

"We're ready to roll," Big Brown's confident trainer Rick Dutrow Jr. said.

Colonel John, who was the second favorite to win the Derby, finished sixth. Pyro, who was also picked by many to be the winner, was eighth.

Matz's Horse Breaks Down

Trainer Michael Matz received good news Saturday. Chelokee, who broke down Friday in an undercard race before the Kentucky Oaks, was given a decent chance to survive as a breeder.

It was originally thought the Chelokee fractured his ankle, but he was instead diagnosed with a badly dislocated ankle. The horse will undergo surgery this week, ending his racing career. He has been given a 50-50 chance of survival.

Chelokee won the Barbaro Stakes last May before the Preakness Stakes.

Barbaro, also trained by Matz, broke down at the 2006 Preakness Stakes after winning the Kentucky Derby. After undergoing surgery and a long recovery, Barbaro was eventually euthanized months later.

Baghdad Derby?

Some National Guard soldiers from Kentucky brought a little Derby tradition with them to Iraq.

The members of the 138th Fires Brigade from Lexington put on their own Kentucky Derby complete with fancy hats, nonalcoholic mint juleps and stick-horse races on Saturday in Baghdad. The racers galloped their makeshift horses around a building at Camp Liberty that served as a desert track.

They even heard a rendition of "My Old Kentucky Home" from the 4th Infantry Division band before the race.

Sgt. George Martinez, the assistant battle captain with the 4th Infantry Division, finished first in the main Derby race.