WATCH: Corner rescues Kell Brook from Gennady Golovkin in spirited but inevitable display

Somebody's O had to go.

And Kell Brook's O went via a thrown towel as the Brit's corner saw enough of Gennady Golovkin's power in the fifth round of their monster clash in London's O2 Arena. The opening rounds were more competitive than many predicted, with Brook arguably taking at least one of the first four frames. It was in the fifth, though, that it appeared as if a switch flicked in the mind of Golovkin, the world middleweight champion.

Wow the towel....nooooo! #GGGBrook pic.twitter.com/SMrpAdOVmc

— Mourinho (@xbioxhazard832) September 10, 2016

The Kazakh fighter began pouring damage on to an already visibly hurt Brook, who began backing up in an attempt to glean some respite from the onslaught. But respite is seldom offered by GGG, who continued storming forward with a barrage of thudding hooks. Brook showed heart early on but once it started to go downhill in the fifth, there was no way he was going to escape the plummet. Golovkin, as predicted, retained his title and status as one of the most terrifying men on the planet. That's 36 fights, 36 wins and, remarkably, 33 knockouts. Best of luck, Billy Joe Saunders.