Martin Nguyen successfully defended his One Championship featherweight (70.5kg) belt yesterday at the Singapore Indoor Stadium, defeating Christian Lee by split decision.
In a fight punctuated by loud boos as both fighters spent the bulk of five rounds circling each other warily, Nguyen did just enough to convince two out of three judges.
The Australian, who has now won 11 of his 13 fights, was aware of the crowd's displeasure.
The 29-year-old said: "I take full responsibility for what happened. That wasn't like me. I'm so sorry Singapore for such a s*** performance. Next time, I promise I'm going to go for the finish."
Lee, 19 and fighting under the Singapore flag, fell to nine wins and two losses, both to Nguyen.
Despite elder sister Angela cheering him on in his corner, Lee appeared tentative against the champion who had beaten him via a first-round submission two years ago at the same venue, with his few attempts at a takedown easily rebuffed by Nguyen.
The Nguyen-Lee bout was the first of three title fights for One Championship's Unstoppable Dreams event last night.
The result of the night's main event between atomweight champion Angela and Mei Yamaguchi was not available at press time.
There was some cheer for Singapore earlier as Amir Khan got back to winning ways with a stoppage victory in the second round of his lightweight fight with South Korean Lee Sung Jong.
The Singaporean had lost to Russian Timofey Nastyukhin in Myanmar in February.
Amir kept to his earlier promise to be more aggressive, as he attacked using a barrage of strikes and defended deftly on the ground, getting out of a tricky looking heel lock in the second round.
"I train with black belts every day with my team-mates at (mixed martial arts gym) Evolve so I wasn't too bothered," said the 23-year-old to loud cheers from the crowd. "Going into this fight, I wasn't about to lose in front of my home crowd."
Amir improved his record to 10 wins in 13 fights, and will hope he gets a title shot at Nguyen next.
Thailand's Yodsanklai Fairtex, the winner of the 2008 TV show Contender Asia, also featured in a kickboxing contest, triumphing over Dutch-Congolese fighter Chris Ngimbi in a unanimous decision.