Matthew Macklin was stunned in 10 rounds in front of a shell-shocked crowd in Dublin.
Jorge Sebastian Heiland proved a handful throughout, giving Macklin a rough night throughout before a pinpoint southpaw right hook sent Macklin down and out in round 10.
Afterwards, Macklin gave his opponent credit and said the finish came from fatigue more than the finishing shot.
John Joe Nevin improved to 3-0 with victory over Jack Heath.
Heath was down early from a body shot and dropped again moments later as an uppercut threatened to undo him. He was floored a third and final time from a right hand before the fight was stopped.
Gary “Spike” O’Sullivan uncorked a huge right uppercut to take out Anthony Fitzgerald inside a round.
There was genuine needle before the first bell as O’Sullivan shoulder barged Fitzgerald when he entered the ring and a couple of minutes later it was all over.
Anthony Crolla warmed up for a January 23 challenge of WBA lightweight champion Richard Abril with a six-round win over Gyorgy Mizsei, taking a 60-54 decision.
Promoter Eddie Hearn confirmed the fight would take place at Manchester’s Phones 4U Arena.
Kal Yafai boxed well and countered smartly on his way to a convincing win over Everth Bricerno. It was one-way traffic with Yafai decking his man three times and Briceno also being deducted a point.