LAS VEGAS – Frank Sanchez survived a surprising scare in the first round Saturday at T-Mobile Arena.

The unbeaten Cuban contender regained his composure after Scott Alexander rocked him with a right hand in the opening round, scored a knockdown in the second round, battered Alexander toward the end of the fourth round and won their scheduled 10-round heavyweight bout by technical knockout on the Canelo Alvarez-Jermell Charlo undercard. Alexander’s handlers instructed referee Robert Hoyle to stop their fight immediately after the fourth round ended because Alexander absorbed too much punishment.

Sanchez improved to 23-0 and recorded his 16th knockout.

Los Angeles’ Alexander (17-6-2, 9 KOs) lost inside the distance for the second time in his past three fights. Chinese southpaw Zhilei Zhang (26-1-2, 21 KOs), who has since won the WBO interim title, knocked out Alexander in the first round of their May 2022 bout at T-Mobile Arena.

Sanchez viciously landed two overhand rights and two right uppercuts during a damaging sequence in the final 10 seconds of the fourth round.

Hoyle warned Sanchez for holding and hitting Alexander about a minute into the third round, but Sanchez otherwise had his way with Alexander during those three minutes.

Sanchez connected with a right hand that made Alexander stumble backward and fall to the canvas 10 seconds into the second round. Alexander complained that Sanchez pushed him, but the replay showed that Sanchez stepped on his foot as he landed that punch, which Hoyle counted as a knockdown.

Alexander landed a right hand to the side of Sanchez’s head that made Sanchez take an awkward step with just under 50 seconds on the clock in the first round. Sanchez stabilized his legs by holding Alexander.

Sanchez drilled Alexander with an overhand right about 40 seconds into their fight.

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