Floyd Mayweather has completed the double after 24 rounds of boxing with Marcos Maidana, and remains the undisputed pound-for-pound champion. He remains unbeaten in 47 contests.
Maidana was not as successful with his aggression as in their first meeting. Mayweather was himself, and employed better movement and tactics.
The stats said it all. Mayweather (47-0, 26 KOs) successfully defended his WBC and WBA welterweight and WBC super welterweight world championship titles with a unanimous 12-round decision victory over Maidana (35-5, 31 KOs) in front of 16,144 fans at the MGM Grand Garden Arena.
There were incidents. Mayweather claimed he was bitten by the Argentine fighter on his fingers in the eighth round, which he said were "numb" for the last four rounds. Maidana was deducted a point for throwing Mayweather to the floor.
Mayweather avoided the arcing punches against the ropes that "El Chino" was so successful with in their first bout and commanded the centre of the ring, landing his straight right-hand repeatedly, while finding openings with his left jab.
The five-division world champion was more effective and efficient this time around, landing 58 per cent of his power punches compared to Maidana's 26 per cent. The 37-year-old also landed 43 per cent of his jabs compared to 17 per cent for Maidana and 51 per cent of his total punches compared to Maidana's 22 per cent.
Their first meeting in May was a majority decision for the 11-time world champion but this time there was to be no controversy in the judges' decisions. Judge Guido Cavalleri had the fight 115-112 while Dave Moretti and John McKaie scored it 116-111.
"He's a tough opponent and I did what I had to do tonight," Mayweather said. "I just didn't stay on the ropes. I have a couple bumps and bruises because he's a wild young fighter. My father told me to hit and not get hit and that's what we did.
"I felt sharper in the first fight. I felt a little dry and dead in this fight. I give myself a C, a C-minus. I could have been better. I got hit with some shots tonight that I shouldn't have gotten hit with. But that comes with the sport."
Maidana disagreed. "I thought I won the fight but if the judges want to give the fight to a guy who runs that's their decision," Maidana said. "I feel like I was the aggressor and I kept applying the pressure. He kept holding and pushing and the ref never did anything about it. Instead, the ref took a point away from me."
Frustrated with Mayweather's circling and arm-holding, Maidana apparently bit his opponent's left hand in the eighth round, causing a break in the fight while referee Kenny Bayless closely viewed the champion's gloves.
"He bit my fingers so my fingers were numb," Mayweather said. "After the eighth round my hand was numb and I really couldn't use my left hand."
"Maybe he thinks I'm a dog, but I never bit him," Maidana replied. "He was rubbing my eyes with his glove. Maybe he had his glove in my mouth, but I don't think I bit him."
WATCH: DID MAIDANA BITE MAYWEATHER?
(warning: video contains strong language)
Mayweather was asked after the fight if he would accept a ring meeting with eight-division world champion Manny Pacquiao.
"I'm not ducking or dodging any opponent," Mayweather said. "If the Manny Pacquiao fight presents itself let's make it happen. I don't know who I'll fight in May but I expect to fight. Manny needs to focus on the guy that's in front of him. Once he gets past that task we'll see what the future holds."
British welterweight Amir Khan was also ringside, and he waits in the wings for his chance. But right now, the choices lie with Mayweather, who is still the king of the world in boxing.