Gennady Golovkin became the unified middleweight champion after stopping home favourite Ryota Murata in Saitama, Japan.

The Kazakh regained the WBA (super) belt, which he lost to Cancelo Alvarez in 2018, to add to his IBF title following a ninth-round stoppage against the former Olympic champion.

Golovkin endured a slow start in what was his first bout in over a year, as he looked to set up a potential rematch with Alvarez later in 2022.

Murata, who won gold at London 2012, directed a series of relentless attacks and body shots to gain the upper hand in the opening four rounds.

But the Japanese fighter was unable to build on his early momentum and Golovkin gradually settled into his flow in round five.

The pendulum began to swing in favour of the 40-year-old, who finally put combinations together and sent Murata's mouthpiece flying in the sixth.

The Golovkin onslaught continued until the start of the ninth; flooring his opponent with a devastating shot and the towel came in from the corner, spelling the 42nd win of his career.