Anthony Crolla will get the chance for revenge against Jorge Linares next February or March, says the British fighter's promoter Eddie Hearn.
Venezuela's Linares relieved Crolla of the WBA lightweight title with a unanimous points victory in Manchester.
However, Crolla gave such a good account of himself that the rematch would probably generate more money.
"There's a rematch clause. It's the biggest fight for Linares. I don't envisage any problems," said Hearn.
"Because Anthony put up such a good fight the 12-13,000 that were in the Manchester Arena for the first fight will increase next time.
"And because the money will be big and Linares will think he can win again, they'll be thinking 'bring it on'."
The 29-year-old Crolla was making the second defence of the title he won from Colombia's Darleys Perez in November 2015.
And former three-weight world champion Linares was a big step up in class, the 31-year-old challenger's boxing ability ultimately trumping Crolla's pressure.
Bizarrely it was the first time Linares had gone 12 rounds in 44 professional fights, including three defeats, especially given that he first boxed for a world title in 2007.
"I felt I had Jorge where I wanted him and he was feeling a few shots, and then he hit me with a hell of a shot and wobbled me in round six," said Crolla.
"It gave him that bit of belief that he needed at the time. I'd love a rematch but I'd have to come back better in order to win. But sharing a ring with a great fighter like Jorge can only benefit me. I'll be smarter than I was this time."
The only realistic alternative is Crolla's old school-mate and WBO champion Terry Flanagan, although promotional differences have nixed the fight before.
Earlier this year, Flanagan accused Crolla of ducking him, only for Hearn to counter that Flanagan did not bring enough money to the negotiating table.
"If there was a huge offer to fight Flanagan we'd consider it," said Hearn.
"But Flanagan is looking for a huge fight himself and Anthony isn't going to be ready until next year."
It has been a chastening few weeks for British boxing, what with Kell Brook losing to middleweight king Gennady Golovkin, Liam Smith losing his WBO light-middleweight title to Saul Alvarez and now Crolla losing to Linares.
In addition, Joe Gallagher, the Ring magazine's 2015 trainer of the year, has seen three of his fighters lose world titles this year, the defeats of Smith and Crolla following on from Scott Quigg's defeat by Carl Frampton in February.
But Hearn added: "A loss at the highest level is never the end of the world. You're not going to win all these fights against great fighters.
"Brook-Golovkin was a war, Liam Smith did great and Anthony just had a great fight against Jorge Linares. It's all about fighting the best guys, that's why British boxing is in such great shape."
Despite recent reverses, Britain still has 12 current world champions.