Tony Bellew and Nathan Cleverly remain on course for a rematch later this year after both men claimed impressive victories in Liverpool on Saturday evening - and then exchanged verbal barbs at ringside as the situation became very tense.
Bellew, topping the bill in his home city of Liverpool, inflicted a first stoppage defeat on Brazilian Julio Cesar Dos Santos. A left hand to the head sent Dos Santos to the canvas in the fifth round and, although the South American managed to beat the count, he remained unsteady on his feet and the fight was waved off.
"I was trying to set him up for the perfect shot and boy did I set him up nicely," said Bellew. "He traded left hooks with me and that's one thing you don't do. It's simple: if you do, you're going to sleep."
Cleverly, who beat Bellew on a majority decision when the pair met for the WBO light-heavyweight title in 2011, had earlier made his second appearance since moving up a weight division.
The Welshman, who lost his world title to Sergey Kovalev last August, stopped Alejandro Valori in the fourth round to improve his overall record to 27-1.
The Argentinian was down in the second round after taking a left hook to the body and Cleverly finished things off with another left early in the fourth.
"I think that's the perfect second fight at cruiserweight," said Cleverly. "It was the same at light-heavyweight where I went through British, Commonwealth, European to the world title. I breezed through those levels with eight straight knockouts when I moved up in weight.
"The same is going to happen at cruiserweight. Bit by bit we're going to increase the level. This is easy for me, let's step it up now in the next fight - you know what's going to happen with that guy from Liverpool."
On the prospect of another fight against Cleverly, Bellew said: "I'm fat, ready and handsome... We both know deep down that I was dead on the scales (in 2011). The tables have turned."