Purists scoffed at New Mexico-bred Peppers Pride when she broke the world record for most consecutive wins. Now they have Mine That Bird to deal with.

Mine That Bird, a 50 to 1 shot with two starts this year at Sunland Park near El Paso, scored the second biggest upset in Kentucky Derby history yesterday, defeating second-placed Pioneerof the Nile by 6 3/4 lengths.

“I wasn’t worried. He’s a small horse and I knew I could squeeze him through,” said jockey Calvin Borel, who brought Mine That Bird flying up the rail, much the same way that he did with Street Sense, when he won the 2007 Kentucky Derby.

It was the greatest margin of victory in the Derby since Assault’s 8-length win in 1946. Barbaro won by 6 1/2 lengths in 2006.

“I didn’t have any real feeling that I could win the Derby,” said New Mexico-based Bennie “Chip” Woolley, the only first-time Kentucky Derby trainer to win in the race’s 135-year history. “They say you are supposed to come with high hopes and low expectations. All I knew is that we’d be more competitive than anybody thought we would.”

Owned by Mark Allen and Leonard Blach, both of Roswell, NM, Mine That Bird was a $9,500 purchase at the 2007 Fasig-Tipton October Yearling Sale. Allen and Blach paid $400,000 for the gelded son of Birdstone, after he won 4 of 5 starts at Woodbine in Toronto and was made Canada’s 2-year-old champion.

Mine That Bird placed second in his first start this year for Allen and Blach at Sunland Park, but finished a disappointing fourth in the Sunland Derby on March 29. He was being pointed toward a stakes race at Lone Star Park in Texas, when richer candidates (Mine That Bird had earnings of $374,381) began dropping out of the Kentucky Derby.

“This is an opportunity you might never get again,” said Woolley, a former rodeo bareback rider who for the past 25 years has primarily trained Quarter Horse runners.

Leonard Blach owns and operates Buena Suerte Equine, a well known New Mexico Quarter Horse and Thoroughbred breeding facility, former home of Quarter racing legends Go Man Go and Easy Jet. Mark Allen’s operates family-owned Double Eagle Ranch in Roswell. His father, Bill Allen, operated Alaskan oilfield service business Veco, and was a witness in the corruption investigation of former Alaskan Senator Ted Stevens.