The Mexico City, Mexico-based sanctioning body announced Cieslak's elevation to full champion on Monday.

The WBC also added that unified WBA/WBO cruiserweight champion David Benavidez is the Polish cruiserweight's mandatory challenger.

Benavidez (32-0, 26 KOs), who won the unified titles with a sixth-round stoppage of Gilberto Ramirez on May 2, is expected to face Cieslak in a three-belt unification on December 12. The fight's victor will then be ordered to face The Ring and Zuffa cruiserweight champion Jai Opetaia (31-0, 24 KOs) next, per the sanctioning body's ruling.

The WBC title was believed to be on the line for Opetaia’s bout against Noel Mikaelian in the co-main event of Ryan Garcia’s second-round stoppage of Conor Benn on Saturday night at T-Mobile Arena in Las Vegas. In its announcement of Cieslak, 37, as the WBC cruiserweight champion, the sanctioning body wrote that the title was actually declared vacant ahead of Opetaia’s ninth-round stoppage of Mikaelian.

Neither Mikaelian nor Opetaia were made aware that Mikaelian had been stripped of the WBC belt before they fought.

Mikaelian (28-4, 12 KOs) was ordered by the WBC to face Benavidez, 29, in late May. A sanctioning body ordering its champion to face a titleholder from another sanctioning body is rare, but it happened in part because Benavidez’s representatives petitioned the WBC to enforce him as the mandatory challenger.

Benavidez entered the ring following Opetaia's victory over Mikaelian and went face to face with him. They shook hands and agreed to fight.

Cieslak (28-2, 22 KOs) won the interim WBC cruiserweight title with a fourth-round stoppage of former light heavyweight titleholder Jean Pascal in June 2025 but has been left waiting since.

Benavidez, No. 1 in The Ring's rankings at both 175 and 200 pounds, also holds the WBC's light heavyweight crown. Ranked fifth on The Ring's pound-for-pound list, the 29-year-old three-division champion told The Ring's Mike Coppinger ringside Saturday night that he would move back down in weight.

When asked for comment, WBC president Mauricio Sulaiman told The Ring: "Cieslak is a tremendous fighter who has been waiting for his opportunity to shine for a long time and now will, against Benavidez."

Cieslak, The Ring's No. 4-ranked cruiserweight, previously made clear his discontent at being held out on the sidelines while being ready and physically able to feature without any news on a return date.

He told The Ring's Anson Wainwright in July of his continued frustration while his team intimated an October timeline was likely then in a homecoming fight, before this development.