Wladimir Klitschko put his career back on track with a spectacular seventh-round stoppage of IBF champion Chris Byrd.
Klitschko had deprived the then WBO champion of his title in December 2000 courtesy of a unanimous points verdict before shock knockout losses to Corrie Sanders and Lamon Brewster left his future in balance.
Often criticised for lack of stamina and chin, Klitschko returned with a brutal knockout of the longest-reigning heavyweight champion.
The 30-year-old sent his opponent to the canvas in the fifth and then again in the seventh, twice battering in brutal rights to the head.
It completed a one-sided trashing for the American, who was taken to hospital for precautionary measures.
"I have never seen someone who took that many blows and still managed to fight on," a jubilant Klitschko said at the post-fight press conference. "He showed a lot of heart."
A crowd of 14,500 in the sold-out SAP Arena not only raised the roof in support of their beloved Ukrainian fighter also but left a lasting impression on Byrd.
"Seeing the crowd I wanted to go out there and just fight and that is hard to do when you are a small guy," a badly bruised Byrd said afterwards. "I was just so pumped up I think I was over-pumped.
We worked out a really good game plan but I really got out of it." Klitschko controlled the fight from the first bell, working well behind his strong left jab and occasionally firing in punishing rights.
A heavy right dusted Byrd early in the fifth but the American showed some incredible chin as he survived the round despite a severe beating from a ferocious Klitschko.
In the seventh, Klitschko then finished another combination with a big right that knocked Byrd down and out.
Klitschko, who also added the vacant IBO crown to his name, admitted he felt almost like reborn.
"It is a very special day for me," he said afterwards. "It is a great feeling. To be back here after going through so many lows is great. The negative moments really helped me and made me a stronger fighter."
Klitschko is the third former Soviet Union fighter to deprive an American of a heavyweight crown after Nicolay Valuev saw off John Ruiz for the WBA belt last December and Sergei Liakhovich edged Lamon Brewster for his WBO crown in February.
On the undercard, Coventry's Steven Bendall fell in his bid to tear the European middleweight title away from Germany's Sebastian Sylvester.
The 32-year-old Brit was a late replacement for Dirk Dzemski, who pulled out of the fight on Wednesday due to a flu virus.
However, unbeaten Sylvester stopped him 57 seconds into the third round when he pinned his opponent to the ropes with a flurry of hard punches, prompting the referee to wave off the contest immediately.
Sylvester started his assault with a big right to the head and followed it up with several hard hooks, which left a dazzled Bendall helpless in the ropes.
The Brit criticised the referee for his decision not to give him a standing count. "Why the hell was he stopping the fight?" a disappointed Bendall said after the fight.
"My head felt clear. He landed two shots. If I got bashed up in the first two rounds it would have been okay but I didn't. Boxing is about taking shots and I ducked into the ropes and the ref jumped in." The defeat was Bendall's second in 26 bouts.