Gennady Golovkin knocked out Mexico's Marco Antonio Rubio in two rounds to retain his WBA/IBO middleweight titles in California. The 32-year-old from Kazakhstan, a 2004 Olympic silver medallist, improved to 31-0 with 28 knockouts, the latest coming 79 seconds into the second round and extending a streak of victories inside the distance that began in 2008.

Golovkin, defending his world title for a 12th time, landed an uppercut to stun Rubio and finished off the fight with a powerful overhand left. Rubio tried to rise but referee Jack Reiss counted him out before he made it back onto his feet. Rubio fell to 59-7 with one draw. Photos by German Villasenor, Sumio Yamada, Naoki Fukuda, Mike Kabooki.