Irish middleweight Andy Lee (L) fighting Matt Korobov for the vacant WBO title on Dec. 13, 2014. Photo by David Becker/Getty Images.

Newly crowned WBO middleweight titleholder Andy Lee was ordered on Friday to make his first defense against mandatory challenger Billy Joe Saunders, according to the organization’s website.

An agreement must be reached by Jan. 12, or else a purse bid will be ordered. The minimum purse bid is $200,000, with 75 percent of the winning bid going to Lee and 25 to Saunders.

A well-traveled, 30-year-old southpaw, Lee (34-2, 24 knockouts) has won six consecutive fights, four by stoppage, since being stopped in the seventh round by Julio Cesar Chavez Jr. in June 2012.

In his last fight on Dec. 13, Lee registered a come-from-behind, sixth-round technical knockout over previously undefeated left-hander Matt Korobov (24-1, 14 KOs) for the title that was vacated by Peter Quillin. Prior to facing Korobov, Lee had earned a come-from-behind, fifth-round knockout of John Jackson in June.

A 25-year-old southpaw, Saunders (21-0, 11 knockouts) is coming off last month’s split-decision victory over previously undefeated Chris Eubank Jr., son of former two-division champion Chris Eubank.

Eubank represented Saunders’ fourth consecutive win over an unbeaten fighter, having followed unanimous decisions over Gary O’Sullivan and John Ryder in July and September 2013, as well as an eighth-round knockout of Emanuele Blandamura this past July.

Saunders-Eubank had been designated an eliminator for the right to face the winner between Lee and Korobov.