Russian Timofey Nastyukhin has spoiled the party for marquee signing Eddie Alvarez at ONE: A New Era in Tokyo, earning a stunning first-round upset win in their Lightweight Grand Prix quarter-final showdown.
The eyes of the martial arts world were tuned in to watch the former UFC lightweight champion make his promotional debut with ONE Championship, after his defection to the booming Asia-based organisation late last year.
But Nastyukhin had other ideas, stealing the show with a heavy overhand right just minutes into the opening round that caught Alvarez behind his ear and folded him to the canvas.
The 29-year-old, just 2-2 in his last four rights, swooped with shots from above to force the referee to intervene and send the packed Ryogoku Kokugikan arena into a bewildered silence.
The 36-year-old looked tentative from the outset and ultimately paid the price for his inactivity against an opponent whose trademark aggression and power formed the ideal recipe for an upset, particularly given Alvarez's increasingly suspect chin.
He was immediately transported to the hospital post-fight with a suspected broken orbital.
Nastyukhin will now advance to fight Hawiian Lowen Tynanes in the tournament's semi-final, the winner of which will earn number one the division's number one contender status.
Alvarez's fellow superstar debutant Demetrious Johnson fared much better, overcoming a stern test from local Yuya Wakamatsu to clinch a second-round submission win in their Flyweight Grand Prix quarter-final.