A packed O2 Arena treated Brook like an insurgent who might bridge the gap in size through raw speed. He walked in at 36-0, while Golovkin carried a 35-0 ledger with 32 stoppages into his 17th defense.
The move carried an ugly warning sign. Four months prior, Amir Khan had stepped up from 147 to meet Canelo Alvarez at 155 pounds, banking early rounds with sharp boxing before a single right hand put him to sleep.
Brook stepped onto a nearly identical path. His fast combinations gave Golovkin real trouble in rounds two and three. Golovkin brought crushing power, yet his upright stance and scarce head movement l
