Bensalem, Pa. - Math Wizard, the second longest shot on the board in Saturday’s $1 million Pennsylvania Derby, pulled off a gigantic upset when he won the Grade 1 stakes by a neck at Parx Racing. Ridden by Irad Ortiz Jr. and trained by 32-year-old South Florida-based Saffie Joseph Jr., Math Wizard rallied down the center of the track and shocked the field that included Preakness Stakes winner War of Will, the beaten favorite in the Kentucky Derby and Preakness in Improbable and a colt that came in with four straight wins in Mr. Money.

Math Wizard went off at odds of 31-1 and paid $64.20, $12 and $4.80. He did not become the biggest longshot to win the Pennsylvania Derby in its 40-year history. That distinction belongs to Valley Crossing, who won at odds of 78-1 in 1991.

“I’ve got to retire now!” an emotional Joseph said after Math Wizard became his first Grade 1 winner in first Grade 1 start. “I feel blessed. I’m at a loss for words.”

Math Wizard won for the third time in 13 career starts. Math Wizard hadn’t won since Jan. 31 at Gulfstream, when he scored by 18 3/4 lengths and was claimed for $25,000 out of that race by his current ownership group led by John Fanelli, who calls Parx his home track.

“This is my biggest win ever,” Fanelli said. “I was screaming so loud, I lost my voice.” Fanelli owns the son of Algorithms along with Collarmele Vitelli Stables LLC, Bassett Stables, Ioannis Zoumas, Wynwood Thoroughbreds and Joseph.

Math Wizard won with a six-wide move into the stretch. He ran down the early pacemakers Mr. Money and War of Will, rallying into slow fractions. The first quarter-mile went in :24.50, the half in :49.60 and 6 furlongs in 1:13.44. With fractions that slow, it would not seem ideal for a closer.

“To me, what was surprising was that the pace was not fast and that horse came from out of it,” said Mark Casse, the trainer of War of Will. The final time for the 1 1/8 mile race over a fast track was 1:50.94.

Ortiz picked up the mount Saturday. Florida-based Edgard Zayas was named to ride Math Wizard at entry time, but he was not at Parx Saturday. “He ran hard,” Ortiz said. “When I turned for home and I opened the reins and he started taking off, I said, ‘I’m going to get there.”

Math Wizard arrived at Parx Thursday with his trainer.

The only horse that went off at longer odds in the field was the maiden Shanghai Superfly, who finished last at odds of 90-1. Every other horse in the field went off at single-digit odds.

“We’ve got the horse going the right way,” Joseph, who is from Barbados. “We just got him at the right time.”

Mr. Money, the 8-5 second choice, finished second for trainer Bret Calhoun and jockey Gabriel Saez and War of Will was third for Casse and Tyler Gaffalione.

“Obviously disappointing,” Calhoun said after Mr. Money’s four-race winning streak ended in his first Grade 1 start. “No excuses. We just got outrun. Kind of surprising to be outrun by a horse we beat pretty handily a couple times.” Mr. Money beat Math Wizard by 11 3/4 lengths in the West Virginia Derby Aug. 3 and by 4 lengths in the Indiana Derby July 13.

Improbable, the 6-5 favorite, got off to a slow start after acting up in the gate and finished fourth, a neck in front of Spun to Run, who was fifth. Improbable also encountered gate problems in the Preakness and he was a non-factor in that race.

“I don’t know why he does it,” Hall of Fame trainer Bob Baffert said by phone from California. “He doesn’t do it in California. Mike (Smith) said he was really good and then heard a noise and it set him off. It’s just frustrating when you go that far and he pulls that stuff.”