Frank Sanchez scores impressive KO of Julian Fernandez on the Canelo Alvarez-Callum Smith undercard

Cuban heavyweight contender Frank Sanchez (17-0, 12 KOs) delivered two vicious right hooks to knock Julian Fernandez (14-3, 11 KOs) through the ropes for a seventh-round knockout victory Saturday night in the Canelo Alvarez-Callum Smith undercard at the Alamodome in San Antonio.

It was an excellent knockout -- a moment that many expected from Sanchez -- albeit a little later than expected.

The 28-year-old started the fight strong, overwhelming Fernandez with his power. But he had some lackluster rounds that allowed an overmatched opponent to stay in the mix even when Sanchez kept Fernandez on the ropes for 11% of the fight, per CompuTrack. Ultimately Sanchez's power was simply too much.

Sanchez, who regularly works with Alvarez and Andy Ruiz Jr. alongside trainer Eddy Reynoso, is knocking on the door to earn bouts with top-10 heavyweight contenders. Sanchez's power is his calling card and he flashed it accurately Saturday in landing 48.5% of his power shots. However, as he moves forward, he will need more than just power to stack up against better fighters.

An improvement in aggression and technique might be necessary, but regardless it was another step forward for Sanchez as he scored what might end up being the knockout of the night.

Castro makes successful debut, stops Valdes in Round 3

Junior lightweight prospect Marc Castro (1-0, 1 KO) beat Luis Javier Valdes (7-6-1, 2 KOs) in his pro debut with a third-round knockout.

Castro came out anxious in Round 1, showing frantic movement and a flurry of wild punches, but he quickly calmed down in the second round after his corner told him to simply slow down. It was then that Castro's skill took over.

For the 21-year-old Castro, it was his precision power punching that was too much for Valdes. He landed knockdowns in Round 2 and Round 3. The latter came with a smooth seven-punch combination to the body and head that dropped Valdes and left him unable to make the 10-count as the referee waved it off.

Castro had a highly decorated amateur career in which he became a two-time amateur world champion and also won multiple Silver Gloves, Junior Olympics and national championships. He began his pro career as the co-main event of a Canelo Alvarez card, a strong start to building a profile.

Ford dominates, stops Lopez in Round 7

Speedy junior lightweight prospect Raymond "Savage" Ford (8-0, 4 KOs) outclassed Juan Antonio Lopez (15-8, 6 KOs) and used a quick right hook to score a seventh-round knockout. The punch dropped Lopez to a knee and he didn't make the 10-count.

Ford controlled much of the fight, which included a first-round knockdown, but he did receive a test from Lopez, who showed some fight in offering tough resistance in the middle rounds. But in the seventh round, it looked like Lopez had no fight left after Ford's go-to right hook landed for the final time.

Ford, a southpaw from Camden, New Jersey, is just 21 years old and already has been a sparring partner for Shakur Stevenson, Jaron Ennis and Tevin Farmer. Saturday, he consistently showed the speed that has people believing in his upside while receiving a nice developmental test from a game Lopez.

Williams demolishes Jones

Exciting middleweight prospect Austin "Ammo" Williams (7-0, 6 KOs) started the night off with a dominant first-round TKO victory over Isiah Jones (9-4, 3 KOs) in a bout that lasted just 91 seconds.

Williams shocked Jones with a vicious left hook that had him badly hurt, then Williams jumped on Jones with relentless pressure to the body before the referee wisely stopped the bout. Jones had never been stopped before, but Williams' quick and powerful hands were clearly too much for him.

Williams was a sparring partner for Callum Smith leading up to Saturday night's fight against Canelo Alvarez. This was a big stage for the 24-year-old southpaw from Houston who jumped into his boxing career late and is hoping to take a step up in competition in 2021.