ARLINGTON, Texas – A much smaller Mexican champion scored a questionable technical knockout on the Canelo Alvarez-Billy Joe Saunders undercard Saturday night at AT&T Stadium.

Mexicali’s Elwin Soto stopped Japan’s Katsunari Takayama in the ninth round of what had developed into a competitive WBO junior flyweight title fight. Takayama withstood trouble in the first two rounds to test Soto with his volume punching, but referee Laurence Cole stopped their scheduled 12-round fight at 2:44 of the ninth round.

Soto had landed several power punches before Cole stepped between them, including a right uppercut and an overhand right. Takayama did not appear on the verge of going down, however, when Cole stopped their 108-pound championship match.

Takayama, a legend among boxers in the lower weight classes, and his handlers protested the stoppage.

Nevertheless, the 24-year-old Soto (19-1, 13 KOs) defended his WBO 108-pound championship for the third time since he won it by knocking out Angel Acosta in the 12th round in June 2019.

The 37-year-old Takayama (32-9, 12 KOs, 1 NC), who has retired from boxing three times, fought for just the second time since August 2016. Before Saturday night, the former IBF minimumweight champion hadn’t been knocked out in 18 years.

In the round before their fight was halted, Takayama continued throwing a high volume of punches. Soto, meanwhile, kept trying to take out Takayama with infrequent power punches in that eighth round.

Takayama threw and landed more punches during the seventh round, but Soto caught him with a clean left hook, the best punch of those three minutes.

A right hand by Soto wobbled Takayama with a minute to go in the sixth round. Soto also got the better of an exciting exchange near the end of the sixth round.

Soto landed a left hook and then a right hand about a minute into the fifth round.

Takayama landed a short right hand inside with 30 seconds to go in the fourth round.

Takayama made the third round more competitive than the first two rounds with his activity and combination punching.

Soto stung Takayama with a right hand about 50 seconds into the second round. Three more rights by Soto landed within the final 15 seconds of the second round.

Soto’s power affected Takayama several times in the first round. A left-right combination by Soto knocked Takayama off balance with less than 10 seconds to go in that opening round.

Then a left by Soto knocked Takayama off balance again just before the first round ended. Soto also hit Takayama with a left hand after the bell to end that first round, which drew a warning from Cole.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.