Undefeated World Boxing Association middleweight champion Gennady Golovkin defended his title by stopping US challenger Curtis Stevens in a fight halted after eight rounds.

Referee Harvey Dock stopped the bout after Kazakhstan's Golovkin unleashed a furious flurry on the challenger that left Stevens dazed and bloody as he went to his corner after the bell.

Golovkin improved to 28-0 with his 25th early-stoppage triumph. It was the 15th fight in a row since 2008 in which Golovkin, 31, has won without needing to go the distance.

Stevens, who was knocked down by Golovkin with a hard right hook in the second round, fell to 28-4.

It was the eighth successful title defense for Golovkin, who won the title by stopping Colombian Nilson Julio Tapia in 2010.