Charles Oliveira claimed the undisputed UFC lightweight title with a thrilling second-round TKO of three-time Bellator champion Michael Chandler.
Brazilian Oliveira extended his winning streak to nine on a dramatic night in Houston, Texas.
The bout formed the main event of UFC 262 at the Toyota Center, where the capacity crowd of 16,000 fans saw Oliveira, 31, produce a thrilling come-from-behind performance to capture the title vacated this year by the retiring Khabib Nurmagomedov.
Before the bout got under way, there was a moment of respect between the pair as Oliveira approached Chandler's corner and embraced his rival before greeting each of Chandler's cornermen.
When the action got under way, the momentum swung back and forth as both men threatened to claim a stoppage victory in a wild opening round.
Chandler connected with a big left hand, which forced Oliveira to shoot for a takedown, but the American immediately locked up a guillotine choke that Oliveira did well to escape from.
Oliveira then switched positions, took Chandler's back and looked to work his way to a rear-naked choke submission. But Chandler exploded his way out of the position and returned to his feet as the crowd roared its approval.
With the fight back on its feet, Chandler loaded up and let fly with his hands as he came close to scoring a first-round TKO finish.
Two big punches hurt Oliveira, who took to the mat in a bid to escape the American's punching power, but Chandler followed him to the canvas and continued landing heavy ground strikes to close out a back-and-forth opening round.
At the start of round two, the bout turned on its head again when Oliveira stepped into striking range and dropped Chandler with a huge left hand.
Chandler quickly got back to his feet, but was clearly still rocked, and Oliveira followed up with more punches that forced Chandler down to the canvas again, where a flurry of ground strikes forced referee Dan Miragliotta to stop the fight 19 seconds into the round.
An elated Oliveira hurdled the cage fence and, after an excited exchange with the UFC commentary team, charged into the crowd to celebrate with the fans before eventually returning to the cage receive his championship belt.
"I told you I was going to knock him out, and I came and knocked him out," said Oliveira after his victory, which gave him the record for the most finishes in UFC history with 17.
"I'm proving to everybody, I'm the lion of lions.