Gennady Golovkin (31-0, 28 KOs) registered consecutive knockout number 18 by stopping weight challenged veteran Marco Antonio Rubio (59-7-1, 51 KOs) in two rounds at a sold-out StubHub Center in Carson, California.
The victory goes into books as the 12th successful defense for Golovkin.
Golovkin, 31, came out firing left hooks.
Rubio landed a right that surprised Golovkin. Rubio had come to fight, but Golovkin was only warming up.
Golovkin went to work in round two. A combination rocked Rubio. He backed away, but the slugger from Kazakhstan connected with a sharp left hook followed by a short uppercut that Rubio never saw. The wannabe challenger staggered into the ropes and ate another left hook that landed flush. Rubio collapsed to the canvas.