With many of the world’s top middleweights unwilling to face Gennady “GGG” Golovkin, the champ is set to take on one of boxing's best welterweights. Moving up from 147 pounds to the 160-pound division, Kell Brook is looking to pull off the upset and defeat the most dominant figure in the sport on Saturday in London.

It’s long been Golovkin’s goal to win all of the middleweight titles, proving he is the best 160-pound fighter in the world. Compiling knockout after knockout, the Kazakhstan slugger has won 22 straight bouts by early stoppage, most recently beating Dominic Wade in the second round to improve his career record to 35-0.

But after retaining the WBO middleweight title in April, Canelo Alvarez decided against a fight with Golovkin, and one likely won’t happen until September 2017 at the earliest. It’s the biggest possible fight that can be made in 2016, but Golovkin was forced to look elsewhere for an opponent.

Enter Brook, who is also undefeated with one more win on his resume. He knocked out Kevin Bizer in the second round of his last fight to retain the IBF welterweight title, and he’s now set for the biggest fight of his career.

Brook finds himself in an unfamiliar position. Often the heavy favorite like Golovkin, most don’t expect the British star to have his hand raised on Saturday.

"Everybody has risk in boxing," Golovkin told ESPN.com. "He's (Brook) moving up and taking that risk and for that I have a great deal of respect for him. Brook is dangerous. He has a very high boxing IQ and we're fighting in his country."

A native of Great Britain, Brook will have the support of the sold-out crowd at London’s O2 Arena, entering the bout as a decided underdog. Golovkin is a -600 favorite at Bovada.lv, and the online sportsbook gives Brook +400 betting odds.

That’s much better odds than most of Golovkin’s opponents have had. While the 147-pound champ is technically moving up two weight classes, he’s indicated that 160 pounds is his ideal weight. Brook weighed in at 159.4 pounds on Friday, while Golovkin came in at 158.9 pounds.

"I feel Golovkin is on edge, he's uncomfortable," Brook said after Friday's weigh-in, via The Telegraph. "I'm ready for this fight. I'm at my natural weight. At past weights I look like I've got my granddad's teeth in I'm that thin but now I feel healthy and I feel ready to put my skills and my chin to the test.

"It's written for me to be out there, in the stars, to win this fight.”

Brook has proven to be one of the sport’s top fighters, but asking him to compete with Golovkin at middleweight might be too tall of an order. Welterweight Amir Khan was competitive with Alvarez for five rounds in May before one punch took him out in the sixth round, and Brook could suffer a similar fate.

Prediction: Golovkin by late-round TKO​