ATLANTA – Troy Isley made a swift, triumphant return to the professional ranks Saturday night after competing in the Olympics over the summer.

The junior middleweight prospect dropped and stopped Nicholi Navarro in the first round of their scheduled four-round fight on the Jamel Herring-Shakur Stevenson undercard at State Farm Arena. The 23-year-old Isley (3-0, 2 KOs), of Alexandria, Virginia, stunned Denver’s Navarro several times during the opening round and eventually caught him with two right uppercuts and a left uppercut that left Navarro crumpled on the canvas.

Referee Brian Stutts immediately waved an end to the action at 2:48 of the first round, as soon as Navarro went down. Navarro slipped to 2-2 (2 KOs).

In the bout before Isley’s quick victory, Roddricus Livsey couldn’t overcome a rough start and Eric Palmer’s counter-punching and suffered his first professional defeat.

Palmer, who took a 12-14-5 record into their six-round welterweight bout, upset Atlanta’s Livsey by split decision. Judges Glenn Feldman and Edward Kanner both scored their back-and-forth fight 58-56 for Palmer, who somehow lost 59-55 on the scorecard of judge Rocky Young. The 38-year-old Livsey’s loss dropped his record to 8-1-1 (4 KOs).

Palmer bounced back from a first-round, technical-knockout defeat to Wesley Tucker in his previous fight, August 5 in Toledo, Ohio.

Seemingly on the verge of pulling off an upset, Palmer clipped Livsey with a right hand that made Livsey hold him with 1:15 left in their fight. Palmer caught Livsey with another right hand just before the final round ended.

Livsey caught Palmer with a right hand in an exchange when Palmer was backed against the ropes with about 1:45 to go in the fourth round. Palmer landed two rights of his own with just under 50 seconds remaining in that fourth round.

Livsey drilled Palmer with a right hand toward the end of the third round. Livsey loaded up on his right hand throughout the first round, but Palmer landed various counter punches and was the more effective fighter in those three minutes.

In the previous fight Saturday night, Haven Brady Jr. endured difficulty against Roberto Negrete to keep his unblemished record intact.

Brady (4-0, 3 KOs), a 19-year-old featherweight prospect from Albany, Georgia, withstood numerous flush right hands and landed enough punches of his own to win all four rounds on the scorecards of judges Pat Cronin (40-36), Glenn Feldman (40-36) and Nola Oliver (40-36). Negrete, of Corpus Christi, Texas, lost for the first time as a pro (3-1, 1 KO).

Brady and Negrete traded right hands during an exchange in the opening minute of the fourth round. Brady landed his fair share of short shots during the final round, but Negrete landed two more right hands late in that round – one with just under 40 seconds to go and another just before that round ended.

Another hard right hand by Negrete moved Brady into the ropes with just over two minutes to go in the third round. By then, Negrete clearly had landed the harder punches past the midway mark of their four-round fight.

Negrete backed Brady into the ropes with a right with just over 50 seconds to go in the second round. That was the cleanest punch of that round.

Earlier Saturday night, Antoine Cobb made a spectacular pro debut.

The 25-year-old Chicago native knocked Jerrion Campbell unconscious with a right hand less than a minute into the first round. Cobb affected Campbell with a right hand a few seconds before he got great extension on a right hand that sent Campbell down awkwardly, with his head draped across the bottom rope.

The official time of the stoppage was 58 seconds of the opening round in what was scheduled as a four-round welterweight bout. Campbell, of Jacksonville, Texas, slipped to 2-2 and was knocked out for the first time in four professional fights.

In the first fight Saturday night, Harley Mederos shut out Deljerro Revello on all three scorecards in a four-round junior welterweight bout.

Brooklyn’s Mederos scored a knockdown after landing a right hand in the middle minute of the first round. The awkward Revello (0-2), of Brighton, Colorado, managed to remain on his feet for the remainder of their bout, as a wild-swinging Mederos (2-0, 1 KO) had difficulty catching the slippery southpaw with flush punches for most of the remaining three-plus rounds.

Mederos won by the same score, 40-35, on each card.

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