Photo: Artur Beterbiev (Instagram) Artur Beterbiev has been told he must defend his IBF light-heavyweight title against his mandatory challenger. This announcement comes just one day after Dmitry Bivol asked for an immediate rematch with Beterbiev. Beterbiev, 39, became the first boxer to hold all four major belts in the light-heavyweight division after winning a close fight against Bivol on Saturday in Riyadh, Saudi Arabia. The judges scored the match 114-114, 115-113, and 116-112 in favor of Beterbiev, a decision that has faced criticism from Bivol's promoter, Eddie Hearn, and manager, Vadim Kornilov. Bivol, 33, has formally requested the support of the WBO, WBA, IBF, and WBC to help him secure a rematch. However, the IBF has now ordered Beterbiev to start negotiations with German fighter Michael Eifert, who is the mandatory challenger. Photo: Artur Beterbiev (Instagram) This does not mean a rematch is off the table. The IBF has stated that Beterbiev can ask for an exception to f...