Charlo twins Jermell and Jermall put on a show Saturday with impressive world title wins in the boxing ring at the Mohegan Sun Arena in Uncasville, Connecticut.

Jermell Charlo knocked out Jeison Rosario with a brutal blow to the body in the eighth round of their super welterweight unification bout.

In his first fight since he won the WBC belt with a knockout of Tony Harrison in December, Charlo added Rosario's WBA and IBF belts to his collection.

Charlo stopped Rosario 21 seconds into the eighth round with a left jab that sent the Dominican sprawling onto his back.

Rosario lay shuddering on the canvas, finally trying to rise but unable to beat the count from referee Harvey Dock.

Charlo, who improved to 34-1 with 18 knockouts, had knocked Rosario down twice -- in the first and sixth rounds -- on the way to victory.

Charlo was credited with a knockdown in round one, when in a wild push forward he backed Rosario up, the Dominican's foot appearing to slip as Charlo landed a hook to his head.

Rosario, who fell to 20-2 with one drawn and 14 wins inside the distance, got Charlo's attention with his punching power.

He backed Charlo into the ropes with a left hook early in the fifth and Dock warned Charlo in the middle of the round for pushing Rosario down by his head.

The fifth ended with a tough exchange, Rosario landing a hard jab before Charlo backed him up with a right.

Rosario came out on the attack in the sixth, but was warned by Dock in the middle of the round for low blows.

Charlo tagged him with a hard left hook that dropped him to one knee shortly before the round ended. He answered the count moments before the bell rang and he still looked wobbly on the way to his corner.

"I definitely proved that I'm more than just a puncher, but I'm also a puncher," said Charlo, who left the ring at the spectator-less arena with all three belts draped around him calling out "Team Charlo!"

Earlier in the evening, Jermall Charlo battered Sergiy Derevyanchenko on the way to a unanimous decision victory to retain his WBC middleweight crown.

The 30-year-old American champion overcame stubborn resistance from the Ukrainian challenger to extend his unbeaten record to 31 fights.

But he was pushed all the way by Derevyanchenko, who fell to 13-3 with the defeat.

Derevyanchenko, bleeding from cuts around both eyes, launched a furious late onslaught in the 12th round as he chased a knockout.

But Charlo, leading comfortably on points, had too much savvy to let victory slip and closed out a third defence of his WBC belt.

- 'I passed the test' -
The three judges scored Charlo a convincing winner, handing the champion victory by margins of 116-112, 117-111 and 118-110.

"I executed the game plan. It was the biggest test of my career and I passed test," he said. "I knew he was going to be tough, and I knew he was going to come to fight.

"I wanted to knock him out and make a statement. But getting through it and getting the decision was a statement in itself."

It was another disappointing defeat for the stocky Derevyanchenko, who had lost two previous world title fights including a disputed decision against Gennadiy Golovkin in October last year.

In other early card action, John Riel Casimero of the Philippines made a successful first defence of his WBO bantamweight crown on Saturday, knocking out Ghana's Duke Micah in the third round.

Undefeated super bantamweight Luis Nery of Mexico earned a 12-round unanimous decision over previously unbeaten compatriot Aaron Alameda to claim the vacant WBC super bantamweight title.

Nery saw his 11-fight knockout streak end, but improved to 31-0 with 24 knockouts while Alameda fell to 25-1 with 13 wins inside the distance.