LAS VEGAS – Southpaw junior lightweight prospect Justin Viloria (6-0, 4 KOs) scored an impressive fifth-round stoppage against gritty Angel Contreras to close out the prelims of the Prime Video show at the MGM Grand on Saturday.

Viloria made a lively start against experienced Mexican Angel Contreras (15-9-2, 9 KOs), landing some flashy lead right hooks and left hands, but he took several straight shots in reply.

There was plenty of give and take, although Viloria opened the second with some classy shots to both the body and head, but Contreras was stubborn and fiery.

The pace didn’t slow in the third, but there was better variety attached to Viloria’s work as he swirled forward and then caught Contreras with counters while on the back foot.

The Mexican’s face was beginning to redden, although he remained a threat with his straight right against the southpaw, who was a little too comfortable to oblige Contreras in close.

That said, the pressure became too much and Contreras was overwhelmed in the fourth and forced take a count after a right hook to the body and one to the head. That only served to encourage Viloria, who became more aggressive still.

The fifth was one-sided, with Viloria in the ascension, Contreras landing less of note and then again being dropped for "nine" by a right to the body. Not short on courage, Contreras made it back to his feet, but after Vilora followed in, he landed the same shot again and Contreras winced in pain and dropped to his knee, and referee Robert Hoyle waved it off instantly.

Time of the stoppage was 2:02 of the fifth. 

"It's something I want to show everyone, what I'm capable of doing," said the 19-year-old Viloria.

Debutant Brayan Gonzalez, from Phoenix, scored two knockdowns in the first round of his pro career but was given a good push the rest of the way in a four-rounder at junior featherweight.

California’s James Mulder was down from a cuffing right hook early and floored from a right-left shortly after.

Mulder managed to score with some rights through the second while Gonzalez deposited his long left downstairs. Mulder occasionally switched, and he got caught by a right hook in the third, but Mulder was busy, determined and refused to be out-fought.

They were swinging at one another through the closing moments of a good fight, and while Mulder is now 0-2, he is better than that suggests.

All four judges scored it 40-35.

Milwaukee’s Daniel Blancas is now 10-0 (5 KOs) after winning in the first frame of an eight-rounder at super middleweight against Germany’s Aro Schwartz, who is 23-8-1 (15 KOs).

Blancas set about his opponent quickly, and although he landed a left hook that shook the European, Schwartz was able to stay upright. Moments later, he was dropped heavily by a left hook, and referee Harvey Dock waved the contest off after 1:50 of Round 1. Schwartz was given time to recover on his stool, where Blanca sportingly checked on him.

Mia Ellis (7-3, 6 KOs), of Baltimore, took early control against Ohio’s Margaret Whitmore (3-0, 2 KOs) and did not stop trying to walk her opponent down. But in a generally even contest, Whitmore had moments of her own, and tried to mix her attacks to the body and head, and they were trading when the bell sounded to end the fight.

Both celebrated after their junior lightweight four-rounder and both expectantly waited for their arms to be raised. Judge Max DeLuca ruled it a draw at 38-38, but he was overruled by two cards of 39-37 for Peggy “The Black Panther” Whitmore.

In a four-round featherweight bout that opened the 100th night of championship boxing at the MGM Grand Garden Arena in Las Vegas, San Antonio’s Reina Tellez improved to 8-0-1 (5 KOs) with a shutout victory over Hungary’s Beta Dudek, who is 4-2 (4 KOs).

Tellez’s early pressure started to reap rewards, and she nailed Dudek with heavy shots from both hands. She kept marauding forward in the second. Dudek tried to stable the ship with her jab, but she was unable to contain Tellez, who was caught off-balance and touched down following a slip.

Near the end of the fourth, Dudek was forced to endure some uncomfortable moments when Tellez cracked her with both hands, and she stayed the course but lost 40-36 across the board.