British lightweight Terry Flanagan has won the vacant WBO title by a technical knockout after an injury to Jose Zepeda.
The fight at the Manchester Velodrome was stopped in the second round after the American suffered a shoulder injury.
Southpaw Flanagan, 26, who is now unbeaten in 28 professional fights, said he wanted a rematch with Zepeda.
"I want to prove that I'm the better boxer," he told Box Nation.
Zepeda had been unbeaten in 23 bouts before Saturday's title fight and only one of his last nine opponents had lasted three rounds.
"I thought he'd just hurt his shoulder," added Manchester-born Flanagan. "I had started to get my range, and I knew I was going to win that fight.
"Now I'm world champion I can start believing in myself. Lifting a world title is unreal."
Earlier Britain's Liam Walsh, 29, beat Brazilian Isaias Santos Sampaio with a sixth round knockout to win the vacant WBO Inter-Continental lightweight title.
Walsh, who also holds the British and Commonwealth super-featherweight titles, is unbeaten in 19 fights.
Meanwhile, heavyweight champion Ruslan Chagaev of Uzbekistan defended his WBA heavyweight belt with a first-round technical knockout of Francesco Pianeta in Magdeburg, Germany.
It was Chagaev's 34th win in 37 fights.
Both fighters had previously lost to world heavyweight champion Wladimir Klitschko, who is set to fight Britain's Tyson Fury in October.
In the Philippines, Donnie Nietes beat Francisco Rodriguez Jr by unanimous decision to win the WBO world light flyweight title.