LIVERPOOL, England — Mon Mome, a 100-1 shot, won the Grand National at Aintree on Saturday, capturing the world's most famous steeplechase by 12 lengths.

The 9-year-old horse was ridden by Liam Treadwell in the grueling 4½-mile test. Mon Mome was the biggest long-shot winner since Foinavon in 1967, who also went off at 100-1.

The winner pulled away after jumping the last of the 30 fences in the 162nd running of the race. Comply or Die, a 14-1 shot who won last year, was second. My Will finished third, ahead of State of Play.

"I had the perfect run through the race," Treadwell said. "He jumped brilliant for me. ... He gave me such a great ride. He was an absolute pleasure to ride. He is so genuine."

Mon Mome, 10th last year, is trained by Venetia Williams, whose career as an amateur jockey ended shortly after falling in the 1988 Grand National.

"It was just unbelievable," Williams said. "The owner was watching the wrong horse for the first part of the race and she thought it was out the back. I'm so proud of the horse. I'm so proud of Liam for giving him such a good ride."