By Jake Donovan

John Vera preserved his unbeaten record in relatively simple fashion, stopping veteran boxer Ayi Bruce in the 4th round of their CBS Sports Network-televised headliner Friday evening in Sloan, Iowa. 

Two knockdowns in round four prompted the stoppage. 

Vera had little difficulty in the evening's main event, sensing the opportunity to deliver a spectacular result. The 27-year old southpaw from Fort Worth, Texas proved his worth in a previous step-up bout, stopping previously unbeaten Radmir Akhmediyev last November in Dallas. 

Against Bruce, there came the opportunity to further expand his power game. The intensity picked up in round four, when consecutive right hooks forced the Ghana-bred veteran to hit the deck. 

Bruce beat the count, but was sent back down moments later. He once again arose during the referee's eight-count and did his best to indicate he was fit to the continue. The third man thought otherwise, electing to stop the contest.

Vera improves to 13-0 (8KOs) with the win, already his second of 2016. Bruce suffers his fourth straight loss, falling to 23-12 (15KOs).

MORE RESULTS TO COME...

Lightweight contender Tony Luis cruised to an eight-round decision win over the suddenly ubiquitous Samual Amoako. Scores were 80-72 across the board in their televised co-feature bout. 

Luis (20-4, 7KOs) was in control from the opening bell, able to force the action as Amoako - while willing to get in there with anyone - is little more than a serviceable opponent in his current comeback tour.

The Ghana native hadn't fought in nearly 11 months before returning last November. Friday's bout is now his fourth in just over three months, including three within the past four weeks. Still, he hasn't won a single round over that stretch, a status that needs to be addressed by the Association of Boxing Commissions if the local commissions are not willing to step in and do the right thing. 

As for Luis, the Ontario-based contender moves to 21-3 (7KOs) with the win, his second straight since coming up just short in a lightweight title fight with Derry Mathews on the road in England last April. 

Baltimore's Malik Hawkins remained unbeaten after scoring a three-knockdown, 1st round knockout of Cody Peterson in a matchup of unbeaten welterweights. The more experienced Hawkins (6-0, 5KOs) - who just turned 20 in January - was too much for the 26-year old Peterson, who was clearly in way over his head in his second pro fight.

Three quick knockdowns came of the night, with Peterson (1-1, 0KOs) giving up after his third trip to the canvas despite the referee's insistence to ignore the request and proceed to count him out.

Sub .500 Jose Silveria delivered an early candidate for Upset of the Year, shocking previously unbeaten Kevin Lavallee in their six-round super featherweight bout.

Scores were 57-56 (twice) and 58-55 in favor of Silveria, who dropped Lavalleee in round three and seemed to do more than enough to win a decision. Instead, the knockdown proved to be the difference between a majority decision draw and the shocker that came of the bout.

Lavalleee (14-1-1, 10KOs) was fighting outside of his native Canada for just the second time in his career, those occasions coming in each of his past two starts. The 25-year old from Montreal just never seemed to get his offense untracked, perhaps unprepared for the aggressive style presented by his journeyman opponent.

Siveria (17-19, 6KOs) had lost 10 of his last 11 starts, including a points loss to Carlos Castro on the same show in Phoenix that saw Lavallee make his stateside debut last September. 

Jake Donovan is the managing editor of BoxingScene.com. Twitter: @JakeNDaBox