Wladimir Klitschko held on to his two heavyweight belts by knocking out Eddie Chambers in the 12th round of their fight in Germany on Saturday night (March 20).

It was the much taller Klitschko who landed a left hook with five seconds left before the final bell rang, knocking Chambers out cold.

The punch was so devastating that Chambers took several minutes to recover before he was able to get back up again.

Aside from a few instances -- including a big right that stumbled Chambers in the second round -- the fight was a snore, as Klitschko jabbed his way throughout.

Chambers gave up five inches in height and 35 pounds in weight, but his speed was supposed to neutralize the Ukrainian's long reach.

It didn't happen though, Klitschko kept him away with his bigger reach and the effective left jab.

"When I was able to get past his jab, I couldn't land any combinations. He worked well with his jab," Chambers said after the fight.

With the win, Klitschko improved to 53-3 and scored his 48th KO. Chambers lost for the second time in 37 fights.

The 33-year-old Klitschko retained his WBO and IBF heavyweight titles.