Shakur Stevenson won the vacant WBC lightweight title to become a three-division world champion when he unanimously outpointed Edwin De Los Santos in Las Vegas.
But it was a hesitant, slow-paced performance at the T-Mobile Arena that contrasted with Emanuel Navarrete's action-packed majority draw with Robson Conceicao on the undercard.
Stevenson made his ringwalk flanked by great fighters, Andre Ward and Terence Crawford. He is clearly a world-class talent but he did not dazzle, as he has done before, against De Los Santos.
- Tyson Fury: I'm all that stands between Oleksandr Usyk and total domination
- Deontay Wilder: All roads lead to fight with Anthony Joshua in 2024
- Stream the best boxing and more with NOW
A southpaw, Stevenson relied on using footwork and single punches, predominantly his lead right. He landed jabs that scored, hinting at his capabilities. But he was far too sparing with any power punches from his backhand.
The styles of the two southpaws did not mesh but De Los Santos struggled too to put the American under pressure.
Stevenson won a unanimous decision, 115-113 and 116-112 twice on the judges' scorecards.
It left De Los Santos frustrated. He condemned Stevenson afterwards.
"I came to fight, he came for a track meet," he said. "He was gifted a title but I am the champion of the people."
Stevenson won the belt, but did not allow himself much in the way of celebration.
"I had a bad performance tonight," he admitted. "I wasn't feeling too good."
That suggested he did have some sort of ailment in the contest. But Stevenson provided no further details.
"I don't make no excuses," he said. " I came here, got the victory, that's all I wanted to do.
"I got to go back to the drawing board and work on a lot of things and come back."
Navarrete came through another thrilling battle. He needed two knockdowns to hold Robson Conceicao to a majority draw and retain the WBO super-featherweight title.
Brazil's Conceicao, an Olympic gold medallist in 2016, was an active and determined challenger. He outworked Navarrete, a rare feat.
But Navarrete responded, ramping up the action and clubbing Conceicao off his feet twice.
The Mexican looped long punches to the body, and directed his attack to the head, with his efforts taking a toll. Conceicao was on uncertain legs at the end of the 11th round. But that did not stop them from engaging furiously in the last.
One judge scored 114-112 for Navarrete, but the other two marked it 113-113, leaving the contest a majority draw.
"I'm happy to come away with the belt," Navarrete said afterwards. "I give a lot of credit to Robson Conceicao. We both did what we said we were going to do. We came out here and we gave the fans a wonderful fight.
"He's a tremendous fighter, his technique is next level and that's what made it so hard," he added.
"I would definitely give Robson a rematch, because he deserves it."