Kenshiro Teraji was too much for an aging Hekkie Budler.
The Japanese 108-pound beltholder stopped his South African counterpart in the ninth round to retain his unified belts on Monday at Ariake Arena in Tokyo.
Teraji (22-1, 14 KOs) was making the third defense in his second reign as champion.
The 31-year-old from Kyoto used a steady attack – including brutal body work – to wear down Budler, who started well but was less and less competitive as the fight progressed.
By Round 9, the former two-division fighter could no longer defend himself. He was taking a series of unanswered punches with his back against the ropes when referee Jose Guadalupe Garcia jumped in to stop the fight.
The official time of the stoppage was 2:19.
Teraji had a wide lead on the scorecards after eight rounds, 80-72, 79-73 and 79-93, meaning one judge had it a shutout while the other two gave Budler only one round each.
The champion has stopped all four of his opponents since he lost a belt to countryman Masamichi Tabuki by 10th-round knockout in 2021, including a third-round KO of Tabuki in an immediate rematch to start his second reign as titleholder.
Teraji became a unified champ by stopping Hiroto Kiyguchi in his subsequent fight.
Buddler (35-5, 11 KOs) had won his first two fights in a comeback but now, at 35, he will be hard pressed to become a three-time champ.