New York ? Kentucky Derby winner Animal Kingdom nearly fell at the start. Preakness winner Shackleford faded in the stretch. The Belmont Stakes was up for grabs.

And it was 24-1 long shot Ruler on Ice who delivered a huge upset Saturday in the final leg of the Triple Crown, splashing his way to a three-quarter length victory over Stay Thirsty.

As expected, Shackleford led from the start but when the field of 12 turned for home in the 11/2-mile Belmont, he tired in the muck as long shots Ruler On Ice and Stay Thirsty passed him by.

“Ruler wasn’t slowing down,” winning jockey Jose Valdivia Jr. said. “It was a great feeling the last sixteenth of a mile.”

The much-hyped rubber match between Shackleford and Animal Kingdom never developed on a rainy day at Belmont Park. Shackleford finished fifth, while Animal Kingdom had a frightful start, never moved into contention and finished sixth.

Jockey John Velazquez nearly fell off Animal Kingdom when the horse was bumped on his right side by Mucho Macho Man just after the start. He somehow managed to get his left foot back into the stirrup, but by then it was too late. Animal Kingdom had dropped more than 13 lengths off the lead, and did well to finish in the middle of the pack.

“The horse almost fell down,” said Graham Motion, Animal Kingdom’s trainer. “Johnny couldn’t believe the horse stayed up. He lost his iron. It took him until halfway around the turn to get his foot back in the iron. It’s disappointing not to give the horse a chance to run his race.”

An elated Valdivia, riding in his first Belmont, described the final seconds of the race while on the gallop back to the winner’s circle.

“I’m a couple of yards from the wire and I’m thinking, ‘Oh my god, oh my god, I’m going to win the Belmont,”‘ he said.

A crowd of 55,779 turned out hoping to see a stretch showdown between Animal Kingdom and Shackleford — the first Derby vs. Preakness winners in the Belmont in six years. But that vanished once the Derby winner was knocked around in a bad bit of racing luck.

“It was unbelievable,” Velazquez said. “They came over on me and clipped heels and I almost came off. I had a horrible trip. No way was he going to make up that much ground. He’s still a great horse.”

The Belmont has a history of surprise finishes, from spoiled Triple Crown attempts to stunning shockers. Only two favorites have won since Thunder Gulch in 1995, and long shots have been the norm. Last year, it was 13-1 Drosselmeyer, two years ago Summer Bird at 11-1, and three years ago Da’ Tara at 38-1.

Birdstone spoiled Smarty Jones’ bid for a Triple Crown in 2004 at odds of 36-1 and Sarava ended War Emblem’s Triple try in 2002 at 70-1 odds.

The win left Lori Hall, who owns Ruler On Ice with her husband George, shaking.

“It was amazing, because we really were the underdog,” she said.

Ruler On Ice’s victory makes it three years in a row a different horse has won each of the Triple Crown races, and next year it will be a 33-year gap since Affirmed swept the Derby, Preakness and Belmont in 1978.

Ruler On Ice, trained by New Jersey-based Kelly Breen, did not run in the first two legs of the Triple Crown. The 3-year-old didn’t have enough graded stakes earnings to qualify for the Derby, but vindicated his trainer’s faith by defeating a field that included the first seven finishers in the Run for the Roses.