Karla Zamora came to Jessica Camara’s home territory with a .500 record and seemingly little chance to win Thursday night.

That didn’t prevent the Mexican veteran from upsetting the former world title challenger by fourth-round technical knockout in a women’s junior welterweight fight that was scheduled for 10 rounds. Zamora’s win was part of the Jean Pascal-Michael Eifert undercard at Place Bell in Laval, Quebec, Canada.

Zamora entered the ring with a 9-9-1 record, but she staggered Camara with a right hand that knocked Camara into the ropes with just under 30 seconds on the clock in the fourth round. An opportunistic Zamora knew Camara was hurt, so she unloaded more than 20 unanswered punches that left the referee with little choice but to step between them and halt the action at 1:46 of the fourth round.

The 29-year-old Zamora (10-9-1, 3 KOs) has mostly competed in lower weight classes, but she became just the second opponent to stop Montreal’s Camara (10-4, 2 KOs) inside the distance.

Camara wobbled Zamora with a right hand late in the second round of their all-action bout, but she couldn’t finish her. That enabled Zamora to get back into their fight during what was a competitive third round.

Continuing to trade with Zamora ultimately cost Camara, who went away from her game plan and slugged against the rugged Zamora.

Three fights earlier, the 34-year-old Camara lost a split decision to Kali Reis (19-7-1, 5 KOs) in their 10-round, 140-pound championship match. Reis retained her IBO and WBA belts and won the then-vacant WBO championship by conquering Camara in their November 2021 bout at SNHU Arena in Manchester, New Hampshire.

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