David Morrell’s first title defense lasted less than a round.

The unbeaten Cuban southpaw demolished Mario Cazares with a left hand to defend his secondary super middleweight title for the first time, by first-round knockout Sunday at The Armory in Minneapolis, where Morrell resides.

Morrell (5-0, 4 KOs), who compiled an amateur record of 130-2 and took a slew of gold medals along the way, buckled Cazares with a straight left hand before following up with the same punch, which folded him.

The 23-year-old outpointed Lennox Allen in August 2020 to win an interim title before scoring a third-round knockout of Mike Gavronski on December 26. Less than a month after his win, the WBA elevated Morrell to “regular champion.”

The 30-year-old Cazares (12-1, 5 KOs), of Mexico, who holds an amateur victory over superstar Canelo Alvarez, was coming off a six-round technical decision over Julio Cesar Chavez Jr. last September. Morrell’s handling of Cazares put his win over JCC Jr into profound perspective.

Fight watchers worried that Cazares had suffered a broken leg as it folded underneath him on the way down to the canvas, but he appeared to be okay.

Morrell may well have instilled an increased level of respect, and maybe even a hint of fear into his fellow competitors at 168-pounds with this breathtaking knockout in just his fifth professional fight.

Cruiserweight Brandon Glanton and Efetobor Apochi delivered in a Fight of the Year caliber performance in the chief support bout. But it was a sixth-round knockdown scored by Glanton that propelled the American to a 10-round split decision victory. Two judges scored it 95-94 for Glanton, while a third somehow had it 96-93 for Apochi, who was outworked for much of the fight.

Glanton (14-0, 11 KOs), 29, a former defensive end for Albany State who picked up boxing at the age of 21, clobbered Apochi with a massive left hook at the end of round six and had his opponent out on his feet. Apochi, who suffered his first loss despite entering the bout with a perfect KO record, was saved by the bell.

Both fighters ran low on petrol in round seven as Apochi seemed to recover from the earlier knockdown. But to begin the eighth round, Glanton and Apochi aimed to take each others’ heads off. Glanton connected with the best punch of the round — a straight right hand — which sent Apochi back into the ropes. With less than 10 seconds remaining in the 10th and final round, the 33-year-old Apochi (11-1, 11 KOs), a Nigeria native based in Houston, connected with a right hand that badly wobbled Glanton, but both men made it to the final bell.

According to Compubox, Glanton landed 187 of 653 punches (29%). Apochi connected on 183 of 721 blows (25%).

On the deeper undercard, All “The Machine Gun” Rivera (22-5, 18 KOs) dropped previously unbeaten Omar Juarez (11-1, 5 KOs) to a knee in round nine enroute to an upset 10-round majority decision in a welterweight contest.

Seasoned veteran Nathaniel Gallimore (22-5-1, 17 KOs) won a well-earned 10-round majority decision over previously unbeaten prospect Leon Lawson III (14-1, 7 KOs) in a junior middleweight affair.

Light heavyweight Atif Oberlton (3-0, 3 KOs) stopped Jasper McCargo (4-2-2, 2 KO) with a left hand to the body in round five.

Also, junior middleweight prospect Travon Marshall (2-0, 1 KO) picked up the victory over Ruben Torres (4-2, 1 KO) in a four-rounder, by unanimous decision.