The bitter baseball rivalry between fans of the Boston Red Sox and the New York Yankees has moved into the stamp collecting world, generating a record number of pre-orders for a series of stamps featuring Hall of Famers Ted Williams and Joe DiMaggio, among others.

According to the U.S. Postal Service, DiMaggio fans have stolen the lead from Williams for the first time since the Stamps Batted In pennant race began in April.

The race -- created to spark a friendly competition among the rival sports fans -- closes Thursday prior to the July 20 to 21 official First-Day-of-Issue dedication ceremonies for the Major League Baseball All-Stars Forever stamps.

USPS officials reported that collectively, fans have hit a grand slam with a record 1.5 million stamps pre-ordered. Never before has the public ordered as many stamps prior to their introduction.

The stamps also include Cleveland Indian Larry Doby -- the first African-American player in the American League -- and Pittsburgh Pirate slugger Willie Stargell.

According to sales figures collected this week, the SBI breakdown is as follows: DiMaggio, 421,266; Williams, 417,066; Stargell, 340,646; and Doby with 332,566.

Earlier this week, Stamp Services manager Stephen Kearney said, "This pennant race is getting more exciting. DiMaggio has dethroned Williams -- for now -- and there’s just a week left for Larry Doby or Willie Stargell fans to take the pennant. We're confident they’ll step up to the plate."

The Postal Service said fans can still pump up the SBI for their favorite player by visiting www.usps.com/play-ball