Murat Gassiev blasted Michael Wallisch away in the fourth round to reassert himself as a heavyweight contender.
The heavy-handed Russian earned a knockout win on Thursday night in Moscow to signal his comeback.
Gassiev floored Wallisch with a body shot, then again with a big overhand right. When Wallisch got up again, Gassiev swarmed him and forced the stoppage.
He picked up the WBA Asian heavyweight title in the process.
It was only his second fight in the past three years, since losing his unbeaten record to Oleksandr Usyk.
In 2018 Gassiev and Usyk held two cruiserweight world championships each and collided in the World Boxing Super Series final - Usyk prevailed on points and will next challenge for Anthony Joshua's heavyweight gold on September 25, live on Sky Sports Box Office.
Since losing to Usyk, Gassiev spent two years out of the ring before reinventing himself as a heavyweight.
He smashed Nuri Seferi inside a round nine months ago and has now slowly started building momentum with another victory. He is still only 27.