ELMONT, N.Y. - A crowd of 52,861 at Belmont Park saw the horse's big move and began cheering as if he were a New Yorker, as Mine That Bird, the gelding who won the Kentucky Derby at 50-1 odds, took the lead at yesterday's 141st Belmont Stakes.

But jockey Calvin Borel and the rest soon realized his little gelding's trademark last-to-first move came too early in the third-and-longest leg of racing's Triple Crown.

Mine That Bird is a son of a Birdstone, who had come from behind to spoil the 2004 Triple Crown bid of Smarty Jones. Here was another Belmont twist: From the back came another fast-closing son of Birdstone, Summer Bird, sweeping to a 23/4-length victory.

"He really exploded the last 500 yards - he had dead aim on the leaders," said Kent Desormeaux, Summer Bird's jockey.

Did Borel, unaccustomed to the expansive Belmont track, move his horse, the even-money favorite, too soon?

"A tad early," trainer Chip Woolley politely put it, surprised to see Mine That Bird in front with two furlongs left.

The 12-1 fifth betting choice, Summer Bird finished the 11/2 miles in 2 minutes, 27.54 seconds, paying $25.80, $9.30, and $4.70. At the end, Dunkirk, the surprising early pace-setter, fought back past Mine That Bird to finish second by a neck.

Five of the last six Belmont winners skipped Preakness, with Afleet Alex the exception in 2005.

Since no horse had a chance at the Triple Crown, only Borel could have made history yesterday. He won the Derby on Mine That Bird, then switched to the filly Rachel Alexandra for the Preakness and won again.

Another of yesterday's twists: Desormeaux, another Cajun, had missed twice in the Belmont when his horse had a shot at the Triple Crown. Real Quiet missed by a nose in 1998, the closest such Triple Crown miss ever, and Desormeaux pulled up a fading Big Brown last year.

"Last year's Belmont was like swallowing a spoon sideways - what a pill to swallow," Desormeaux said.

Yesterday was just Summer Bird's fifth career start, and 34-year-old trainer Tim Ice had brought the Louisiana-based colt - owned by husband-and-wife doctors who are natives of India - straight to Belmont Park after Summer Bird had finished sixth at the Kentucky Derby.

"Tim had the horse breathing fire. The previous mounts walked to the gate," Desormeaux said, referring to Real Quiet and Big Brown. "I thought it was maturity. But this horse showed me the difference. I mean, he was toey, dancing - just that bit of energy that tells you, 'Let me at them, I can't wait to get to them. I want to be a racehorse.' The other ones, they were kind of just, 'Here we go again.' "

Borel, an easy guy to root for, had guaranteed victory for Mine That Bird, said it was "in the bag." But the jockey based at Churchill Downs, who has won the Kentucky Derby twice, is 0-for-5 lifetime on the dirt at Belmont Park. Borel talked afterward about how his horse had taken him to the front a little earlier than he had planned after he had eased Mine That Bird away from the rail. Once the gelding got outside, Borel began riding him.

"I thought I was home-free . . . nothing but racetrack in front of us," Borel said of Mine That Bird. "No excuses. . . . He bellied down and ran his little heart out. Please, don't knock him down."

Nobody can rip the Derby winner, who also finished second at the Preakness, the only horse to hit the board in each of this year's Triple Crown races. Woolley said he had been concerned taking the horse to the detention barn yesterday that Mine That Bird had been "a little amped up - maybe I had him a hair too fresh."

While Desormeaux went six wide to find a clear path for Summer Bird, Borel was already up ahead whipping his horse. Leaving the track, the jockey got another kind of familiar New York cheer.

"Calvin - next time don't talk too much, Calvin," yelled a guy from the grandstand.