Rendall Munroe emerged from retirement with a first round stoppage victory over Hungarian Lazslo Fekete in Leicester.
The former European champion and world title contender said he would quit the ring following defeat to Scott Quigg before Christmas.
However, the 'Boxing Binman' re-found his hunger for the sport and announced his return with a devastating finish in front of his home fans at the Club Republic nightclub.
Fekete had a puncher's record - five off his six wins were by knockout - but Munroe was too big, too strong and hit too hard.
He walked his opponent down, then blasted the Hungarian to his knees with a left-right-left.
Fekete beat the count, but referee Rob Chalmers waved the fight off after just 101 seconds.
"My biggest fight was with the scales and stepping up in weight was definitely over due," said the 32-year-old, who scaled a career-heavy 9st 7lbs 6ozs.
"I retired because I was disappointed with the lack of opportunities I was getting. But I'm back and now it's all about having fun again."
Munroe attracted a sell-out crowd to the city-centre nightclub and could be back in action there in October.
"I leave who I'm fighting down to my management," he added. "But there's no reason why I can't bring a world title back to Leicester."