Get ready for the fourth chapter of the Arthur Abraham-Robert Stieglitz rivalry.

Abraham (42-4, 28 KOs), who retained his super middleweight belt by decision in a rematch with England's Paul Smith on Saturday, was expected to next defend against former four-time middleweight titlist and fellow German star Felix Sturm in what would be a really big fight in their country.

However, on Wednesday the WBO ordered Abraham and former titlist Stieglitz (47-4-1, 27 KOs), also of Germany, to meet in a mandatory fight. The sides have 20 days to make a deal or a purse bid will be ordered.

In August 2012, they met for the first time and Abraham won a competitive decision to dethrone Stieglitz. They met again in March 2013 and Stieglitz knocked out Abraham in the fourth round to reclaim the 168-pound title. And then they met for the third time in March 2014 with Abraham scoring a 12th-round knockdown and winning a dramatic split decision to win back the title.

Stieglitz is coming off a split draw with Sturm in an excellent fight in November.