Japan's Ryota Murata, fighting for the first time in over two years, lost his WBA super world middleweight championship to IBF champ Gennadiy Golovkin of Kazakhstan by technical knockout in Saturday's title unification bout.

Fighting for the first time since December 2019, Japan's 36-year-old London Olympic gold medalist, Murata's record fell to 16-3. Golovkin, fighting a day after his 40th birthday, improved to 42-1 with one draw and 37 wins by knockout.

"Golovkin just overall out-boxed me," Murata said.

WBA middleweight super champion Ryota Murata (R) of Japan punches IBF champion Gennadiy Golovkin of Kazakhstan during the sixth round of their title unification bout at Saitama Super Arena on April 9, 2022. (Kyodo) ==Kyodo

The Japanese champ continually attacked in the early rounds at Saitama Super Arena outside Tokyo, with Golovkin content to back off, absorb punishment and make Murata miss when he could with only occasional surprise counterattacks.

By the fifth round, the momentum began to swing, as Golovkin attacked more and more, and began pinning Murata back into the ropes. By the ninth round, Murata had trouble launching any counters.

When he eventually lost his footing and slipped to the canvas, Murata's corner called for an end to the fight.

"Murata was a true warrior and fought to the end," Golovkin said as his team applauded the former Olympic champion.

The fight was scheduled for Dec. 29, but was postponed when Golovkin was unable to enter Japan due to coronavirus border restrictions.

He and his entourage finally arrived in Japan on March 31, while he and Murata were living and training in "bubbles" in the lead up to the bout.

"I think I'm the luckiest man in the world to be able to fight Golovkin after not having a fight for two years and four months," Murata said.

In the undercard, WBO flyweight champion Junto Nakatani defended his title for the second time, beating Japanese compatriot and second-ranked challenger Ryota Yamauchi by eighth-round technical knockout.

With their fighter getting pummeled from the start of the eighth round, Yamauchi's corner threw in the towel.

"I just fought the way my seconds instructed me, he is a good puncher, so I had to stay focused from the first round. I learned a lot about myself from this fight."

"I still have a long way to go in fights here and abroad, however, in my quest to be a great pound-for-pound fighter."

The 24-year-old Nakatani improved to 23-0 with his 18th knockout, while Yamauchi, 27, dropped to 8-2.

IBF middleweight champion Gennadiy Golovkin (L) of Kazakhstan punches WBA champion Ryota Murata of Japan during the fifth round of their title unification bout at Saitama Super Arena on April 9, 2022. (Pool photo) (Kyodo) ==Kyodo

IBF middleweight champion Gennadiy Golovkin (R) of Kazakhstan sends WBA champion Ryota Murata of Japan to the canvas during the ninth round of their title unification bout at Saitama Super Arena on April 9, 2022. (Pool photo) (Kyodo) ==Kyodo

IBF middleweight champion Gennadiy Golovkin (L) of Kazakhstan acknowledges the crowd after beating WBA champion Ryota Murata (R) of Japan by technical knockout in their title unification bout at Saitama Super Arena on April 9, 2022. (Kyodo) ==Kyodo