Kentucky Derby winner Orb, seeking to break a Triple Crown drought that stretches back to 1978, struggled through the last half of the Preakness and finished fourth, trailing the winner, Itsmyluckyday and Titletown Five.
"I'm disappointed," said Orb's trainer, Shug McGaughey.
Winning trainer D. Wayne Lukas, who picked up the sixth Preakness win of his long career, said ruefully, "I get paid to spoil dreams ... you still have to line them up and win."
Gary Stevens, who came out of a seven-year retirement this year, took Oxbow to the lead as the field headed past the finish line for the first time, set a comfortable pace with no pressure and had no trouble holding on through the stretch to win by 1 3/4 lengths.
"When I hit the 1/2-mile pole, I said, 'Are you kidding me?'" said the 50-year-old rider. "'Is this really happening?'"
Stevens said Oxbow, a son of Awesome Again, "staggered home a little bit in the last sixteenth" but by then none of his rivals was making up any ground.
Oxbow finished sixth in the Kentucky Derby and before that was fifth in the Arkansas Derby. Saturday's win was his third in 11 starts. Lukas had branded him a hard-luck case as he suffered through a series of bad post position draws after winning the Grade III LeComte Stakes at Fair Grounds in January.
Lukas said before the race Oxbow finally got a draw that might work to his advantage.
McGaughey said Orb may have been compromised by his trip, starting from the rail and getting stuck on the inside, amid traffic.
"He just never was real comfortable when he got down in there," McGaughey said.
But jockey Joel Rosario said Orb "just had a hard time to keep going" after the first 1/2 mile of the race. "I was worried a little bit," Rosario said.
With the Derby winner struggling in the Preakness and the Preakness winner having "staggered home" in the 1 3/16-miles Preakness, the picture is clouded for the 1 1/2-miles Belmont Stakes, the third jewel of the Triple Crown, set for June 8 in New York.