The Charlo twins will co-headline a Showtime pay-per-view broadcast on September 26 against their most significant tests to date.

Jermall Charlo will defend his WBC middleweight title against No. 1 contender Sergiy Derevyanchenko. His twin brother, Jermell Charlo, will square off against Jeison Rosario in a junior middleweight title unification as part of a six-bout card from Mohegan Sun in Uncasville, Connecticut.

The Charlo doubleheader was the first of seven cards announced on Wednesday morning that will land on either cable or pay-per-view. Each of those cards, beginning August 1 and ending December 12, will take place at the Mohegan Sun Arena without fans due to COVID-19 restrictions.

According to Showtime’s official press release, the Charlo-Derevyanchenko and Charlo-Rosario contests are both considered main events with their own pair of chief support bouts.

Brandon Figueroa (20-0-1), 15 KOs) will take on Damien Vasquez (15-1-1, 7 KOs) in the first Charlo-Derevyanchenko undercard fight. Then, Diego Magdaleno (32-3, 13 KOs) will face Isaac Cruz (19-1-1, 14 KOs) in an IBF 135-pound title eliminator.

On the Charlo-Rosario portion, unbeaten junior welterweight Mario Barrios (25-0, 16 KOs) will fight Ryan Karl (18-2, 11 KOs). But the last fight could be the most entertaining on the preliminary show as Daniel Roman (27-3-1, 10 KOs) and Emmanuel Rodriguez will battle in a WBC junior featherweight elimination bout.

Four belts will be on the line when Charlo (33-1, 17 KOs), 30, of Houston, Texas, and Rosario (20-1-1, 14 KOs), 25, a native of Dominican Republic who trains out of Miami, meet in the ring.

Charlo regained the WBC title last December when he avenged a controversial loss to Tony Harrison almost exactly a year prior with an 11th-round knockout in Ontario, California. Rosario lifted the IBF and WBA 154-pound championships from Julian Williams in January in a massive upset when he battered the Philadelphia fighter in a fifth-round stoppage.

The Ring’s vacant 154-pound championship will also be on the line with the winner becoming the official “top dog” of the division.

Charlo predicted a knockout of Rosario.

“It was always my dream to win multiple belts,” Charlo said. “(You should) expect for me to get that win. I won’t leave it up to the judges. I learned that in my past, and these are the things that I have to do.

“I either have to win (in dominating fashion), or I have to win by knockout.”

The 34-year-old Derevyanchenko (13-2, 10 KOs) chose a Charlo fight over a lucrative offer to move up to 168-pounds to face superstar Canelo Alvarez (53-1-2, 36 KOs).

Derevyanchenko will get his third shot at winning a middleweight title in his past four fights. The Ukrainian was outpointed for the vacant IBF 160-pound championship by both Daniel Jacobs (36-3, 30 KOs) and Gennadiy Golovkin (40-1-1, 35 KOs), surviving first-round knockdowns in both fights to give both men some of the toughest battles of their career.

Charlo, a former junior middleweight titleholder, is coming off a seventh-round TKO of Ireland’s Dennis Hogan on December 7 at Barclays Center in Brooklyn.

Since moving up to 160-pounds nearly three years ago, Charlo has defeated the likes of Jorge Sebastian Heiland, Hugo Centeno Jr., Matt Korobov, Brandon Adams, and Hogan. However, Derevyanchenko is a significant step-up in competition.

Charlo on possibly knocking out Derevyanchenko: “It will definitely make a statement that the power is for real and I can get in there with just about anybody.”