For Brooklyn’s Lanza brothers, Santa Claus came late, in the form of a white Eli Manning jersey.

The top-selling item at the brothers’ Legends Sporting Goods store in the Bay Ridge neighborhood this week was a $250 shirt with a no. 10, the number worn by the New York Giants quarterback who led his 12-point underdogs to victory in the last seconds of this year’s Super Bowl.

“You couldn’t sell a Manning jersey all year,” Peter Lanza said in an interview at his 27-year-old store. “It’s like Christmas in February.”

The Lanzas, who considered cutting staff this year after a “horrible” holiday season, are reaping the rewards of the Giants’ 17–14 win over the undefeated New England Patriots. This year’s championship game may generate more than $125 million of Super Bowl-brand clothing sales, beating the 1997 record, according to a spokesman from the National Football League, Brian McCarthy.

Modell’s Sporting Goods, a New York-based retailer with 135 locations in the Northeast — including Patriots territory in New England — has also had a windfall.

“It’s been tremendous for us,” an executive vice president, Bill Barrett, said in an interview at a store near New York’s Grand Central Terminal. “We had a steady stream of customers. It was nuts from opening to closing.”

Modell’s, like most American retailers, is seeking ways to drum up customer demand while consumers pare spending in the face of higher food and fuel costs and a slumping housing market.

“We’ve had our ups and downs over the course of the year,” Mr. Barrett said. “Something like this is gravy for us.” Modell’s is closely held.

A team of executives worked on the logistics of getting merchandise to the 85 stores in the metro area in what Mr. Barrett called “a very meticulously planned effort.”

Seven printers starting churning out jerseys, shirts, and hats after the game concluded around 10 p.m. By 4 a.m. the day after the game, the goods were in stores, Mr. Barrett said, two hours before the Times Square store opened its doors.

Inside the Modell’s near Grand Central Terminal, customers could choose from dozens of goods, including a $35 tapestry with the score embroidered on it, a $6 Super Bowl championship baby bib, and a $75 replica jerseys.

The Lanzas in Brooklyn sold 144 $30 Super Bowl caps the day after the game. They’re shipping orders from their Web site to as far as Russia. They also have a Staten Island store. And they’re looking for extra help.

Internet sales of Super Bowl merchandise after the game rose 80% from last year, a vice president for the National Football League, Susan Rothman, said.

Not every merchant prospered. Near the parade route in Lower Manhattan, Warren Longmore, a street vendor, got a lesson in supply and demand.

Mr. Longmore’s Super Bowl victory shirts were languishing, undercut by a competitor down the block selling the same thing for $10.

“We sold a few of them, but not many, because they’re $20,” he said from his perch at Broadway and Fulton Street.