German southpaw Viktor Jurk (14-0, 12 KOs) walked out from the corner for his May 15 bout with Edwin Castillo (13-3, 8 KOs) and threw a left hook that instantly dropped the Colombian flat on his back, completely knocked out cold.
The official time of the stoppage was 15 seconds, but it was all over way before that.
Barry Jones described the performance from ringside as "menacing".
26 from Flensburg, Germany, Jurk was an outstanding amateur with two wins over Anthony Joshua's prospect, Emanuel Odiase.
The 6ft 9ins towering heavyweight contender Jurk is now unbeaten in 14 pro bouts with an 85% KO ratio. If he was unknown to any fight fans before yesterday, he won't be now, and that
Castillo was motionless for some time, but was fortunately able to stand for the result to be read out.
Boos rang out around the SAP Arena after Frankfurt cruiserweight Alexander Okafor was ruled a split decision winner over Elija Uelkuseven.
It seemed Uelkuseven had outworked the eventual winner but while one judge scored it 96-93 in Uelkuseven’s favour, two judges preferred Okafor by 95-94, which was not well received by the spectators.
At lightweight, Devrim Goekduman, from Karlsruhe, Germany, is now 13-0-1 (8 KOs) and Franklyn Dwomoh is 9-0-1 (2 KOs) after a hard-fought draw. Scores were 95-94 each way and 94-94.
Hamburg's Dwomoh had the great Roy Jones Jr in his corner and the decision was booed as neither fighter looked satisfied by the outcome.
Dwomoh sometimes stayed in the pocket for too long and was caught by both left hooks and right hands in the third, although he landed a hook of his own that the judges surely would have seen.
He started the fourth swiftly, soon having Goekduman down on the canvas and then blitzing him with a follow up assault. However, Dwomoh punched himself out and his volume dimished allowing Goekduman to come surging forward. A right to the body momentarily slowed Goekduman, but he ended the round on the front foot.
Goekduman maintained his aggresion and dominance in the fifth stanza, but the pace slowed in the sixth.
Dwomoh was bundled to the floor a couple of times and he came through some rough moments in the seventh when Goekduman backed him up with a straight right.
Dwomoh was in there throwing to the end, landing with a strong left hook in the final 10th stanza, but he had not done enough.
Earlier in the event, unbeaten middleweight Oluwole Jan Ciosek moved up to 5-0 (2 KOs) with an eight-round decision over Washington’s, Shae Green, who is now 9-2-1 (2).
Debutant Edmon Avagyan scored a three-round stoppage of 13-8-2 (8 KOs) Patrik Fiala at cruiserweight.