Thailand's Wanheng Menayothin is likely to get a rematch with compatriot Panya Pradabsri, who dethroned him on Friday, his handlers said on Saturday.
Unheralded Panya, 29, stunned holder Wanheng to claim the WBC minimumweight title in Nakhon Sawan.
All three judges scored it 115-113 in favour of the challenger from Ubon Ratchathani, who was ranked third before the bout.
The new champion, who is better known in Thailand as Petchmanee CPF, improved to 35 wins and one loss with 24 knockouts.
It was his first world title shot, having previously been WBC Asia champion.
The outcome snapped the undefeated record of Wanheng who dropped to 54-1 (18KOs).
It was his first bout in over a year after he beat South Africa's Simpiwe Konkco in October 2019.
"I think Wanheng was clumsy because he had not fought for a long time," said his promoter Piyarat Vachirarattanawong.
"With travel restrictions, it is likely the two boxers will meet again."
It remains difficult to travel to and from Thailand due to the Covid-19 pandemic although people in certain categories are allowed to do so.
Wanheng, whose real name is Chayaphon Moonsri, became more well known after he surpassed Floyd Mayweather's 50-0 record in 2017.
His handlers have signed a deal with Golden Boy Promotions for Wanheng to fight in the US.
The boxer, known in Thailand as Wanheng CPF, was scheduled to make his US debut earlier this year but it was cancelled due to the coronavirus outbreak.
He later announced his retirement but was persuaded to continue fighting just a few days later.