LAS VEGAS _ Floyd Mayweather Jr. closed out his distinguished career at 50-0. And UFC champion Conor McGregor lasted into the 10th round in his pro boxing debut against the five-division champion.
So, both men could declare victory Saturday in their novelty boxing match at T-Mobile Arena.
Mayweather's strategy was timed perfectly as he set aside the ills of age at 40 and hammered McGregor with a series of late punches to set up a 10th-round technical knockout victory.
"He's a lot better than I thought he was, but I was the better man," Mayweather said after starting slow in the first four rounds, as McGregor landed some clean jabs, punches and even some dubious mixed martial arts-inspired hammer fists to the back of the head.
But after that, Mayweather reverted to the master tactician who knows how to win rounds, peppering McGregor with an impressive three-punch series of right hands in the sixth round.
His accuracy and tempo increased into the ninth, when McGregor resorted to desperate holds after being hurt by blows.
In the 10th, Mayweather crushed McGregor with three hard rights as part of an onslaught that persuaded referee Robert Byrd to stop the fight 1 minute, 5 seconds into the round.
"I guaranteed everybody this fight wouldn't go the distance," Mayweather said.
McGregor proudly hung in as total punches landed were 88-82 in Mayweather's favor through seven rounds.
"He's composed. Not that fast or powerful, but, boy, is he composed," McGregor said.
McGregor said he thought Byrd should have let the fight go on even though he didn't dispute the stoppage immediately in the ring.
"Let me try to recompose myself," McGregor said. "I'm brand new to the sport."
Earlier in the evening, referee Russell Mora controversially awarded Gervonta Davis an eighth-round knockout victory on a left-handed punch that struck opponent Francisco Fonseca in the back of the head.
Davis lost his belt by missing weight even before fighting Saturday and his inattention in the ring also led to a more difficult bout than he expected.
Davis (19-0, 18 knockouts) said he hurt Fonseca with a body blow before the fateful punch, and explained that the disputed shot "capped" the damage, although fans who watched replays in the arena voiced disapproval of that notion.
"Everyone saw I was going down from a blow that was not legal," Fonseca said. "I want a rematch. ... He didn't hit as hard as he says he does."
The bout served as the co-main event to the Mayweather-McGregor match.
The start of Mayweather-McGregor was delayed briefly, according to Showtime, due to a rash of last-minute pay-per-view orders and system outages.
"We have reports of scattered outages from various cable and satellite providers and the online offering," Showtime said in a statement. "We will delay the start of the main event slightly to allow for systems to get on track."
Davis lost his belt by weighing 132 pounds, two over the junior-lightweight limit, on Friday, putting the International Boxing Federation title on the line only for 40-1 underdog Fonseca, who sought to pull off a stunning upset.
Fonseca (19-1-1) rocked Davis so hard with a punch in the seventh, the former champion had to grab the ropes to remain standing.
Davis came out swinging with aggressive uppercuts to open the bout, trying to end the fight impressively, but he was locked in a tougher test than he anticipated.
Davis, after working out under Mayweather's guidance and training feverishly in a rubber suit Thursday night, revealed again the difficulty some boxers have in making weight.
He apologized on Twitter after Saturday's bout, posting, "I'm young. I'm growing. I had a chance to make the weight. I knew I couldn't make it and that's that. I will have a belt again.
"I lost the belt, not a fight. ... I will make it up."
That left Davis' stablemate at Mayweather Boxing Club, former super-middleweight champion Badou Jack, to fight for a belt. He succeeded, stopping Nathan Cleverly by fifth-round technical knockout for the World Boxing Assn. light-heavyweight title.
Jack out-landed Cleverly in punches, 172-82, rocking the Welshman with blows in the fourth round, then unloading a barrage of punches in the second half of the fifth and looking to referee Tony Weeks to stop the abuse.
Weeks stopped the punishment 2:47 into the fifth.
"It's a dream come true," said Jack, who is from Sweden. "You can't leave it in the hands of the judges. You've got to go for the kill."
Jack (22-1-2, 13 KOs) said he'd like to fight World Boxing Council champion Adonis Stevenson next, and criticized Stevenson for taking a string of unimpressive opponents.
"Let's get real," Jack said.
Earlier, unbeaten cruiserweight Andrew Tabiti improved to 16-0 with a unanimous-decision triumph over veteran former champion Steve Cunningham by scores of 97-93, 97-93, 100-90.
Replacement opponent Yordenis Ugas (20-3) twice knocked down welterweight Thomas Dulorme and proceeded to an upset victory by decision on scores of 93-92, 93-92, 94-91.
The loss was clinched because Dulorme (24-3) had two points deducted for low blows in the sixth and 10th rounds.
