Mine That Bird dug up a miracle for a stunning win in the Kentucky Derby with a dynamic run through the mud at Churchill Downs.The three-year-old gelding and jockey Calvin Borel found room along the rail at the top of the last straight then pulled away for a 6-3/4 length win in the second biggest upset in the race's 135 years.His margin on Saturday (Sunday AEST) was the largest since Assault won by eight lengths in 1946."It was a Street Sense move," Borel said, referring to the same rail-hugging

Mine That Bird dug up a miracle for a stunning win in the Kentucky Derby with a dynamic run through the mud at Churchill Downs.

The three-year-old gelding and jockey Calvin Borel found room along the rail at the top of the last straight then pulled away for a 6-3/4 length win in the second biggest upset in the race's 135 years.

His margin on Saturday (Sunday AEST) was the largest since Assault won by eight lengths in 1946.

"It was a Street Sense move," Borel said, referring to the same rail-hugging ride he gave that colt to win the Derby two years ago.

"They can only go so fast, so far. When I hollered at him, he just went on."

Sent off at 50-1, Mine That Bird ran the 1-1/4 miles (2000m) on a sloppy track in 2:02.66 and paid $103.20 to win - the second-largest payout in Derby history behind Donerail ($184.90) in 1913.

Pioneer of the Nile finished second for newly installed Hall of Fame trainer Bob Baffert, a three-time Derby winner.

Musket Man was another nose back in third followed by Papa Clem.

Friesan Fire the 7-2 favourite was 18th in the 19-horse field.

Earlier, I Want Revenge became the first morning-line favourite to be scratched on Derby Day after inflammation was detected in the colt's left front ankle.

The injury wasn't believed to be career-threatening but worrisome enough to prompt trainer Jeff Mullins and owner David Lanzman to withdraw.

Mine That Bird was squeezed coming out of the starting gate but Borel took a firm hold and wrestled the horse to the rail while they were in last place.

They were 12th and going strong with a quarter of a mile (400m) to go, after working their way around Atomic Rain.

Borel quickly angled Mine That Bird back to the inside and shot the gelding through a tight spot.

"I had enough room," Borel said. "He's a small

horse."

Once free, Mine That Bird quickly accelerated toward an improbable victory.

"I salute Calvin for his terrific ride," said trainer Todd Pletcher whose Derby losing streak extended to 24 races.

"It's an amazing story. It just shows you how special this race is. Anything can happen."

Bennie Woolley Jr, a former quarter horse trainer who spent time on the rodeo circuit as a bareback rider, hobbled on crutches to the winner's circle.

The 45-year-old self-described cowboy from New Mexico broke his right leg in a motorcycle accident two months ago.

"I'm feeling like I never have before," Woolley said.

"I was just blown away."

Borel became the first jockey since 1993 to complete the Oaks-Derby double, having ridden Rachel Alexandra to an eye-popping 20 length victory on Friday.

Woolley joined a parade of trainers to win with their first Derby starter, the sixth time in seven years it has happened.

"Those cowboys," Baffert said. "They came with a good horse."

Mine That Bird, a son of 2004 Belmont Stakes winner Birdstone, became the ninth gelding to win the Derby and just the second in the last 80 years following Funny Cide in 2003.