Updated

Gennady Golovkin stopped Grzegorz Proksa in the fifth round of an impressive American debut Saturday night.

Golovkin (24-0, 21 KOs) battered his Polish opponent in every round, dropping Proksa (28-2) in the first and fourth rounds before the referee halted the bout. Golovkin defended his WBA and IBO middleweight belts with his 11th consecutive stoppage victory.

Golovkin is a Kazakh-born fighter who lives in Germany and trains in California. He had never fought in the U.S. before this bout at a casino in upstate New York, but he is determined to become a stateside star.

Golovkin's impressive performance puts him among the world's top middleweights, although his raw talent could make him unattractive to the winner of Sergio Martinez's fight with Julio Cesar Chavez Jr. on Sept. 15.