Former champion Sergey Lipinets topped Omar Figueroa Jr. live on Showtime.
The event took place from Hollywood, Florida under the Premier Boxing Champions banner.
Alberto Puello claimed the vacant WBA 140-pound title, while Hector Garcia and Brandun Lee also picked up wins.
Lipinets, who took the fight on five-days-notice, floored Figueroa (28-3-1, 19 KOs) with a short, compact counter right hand with a minute left in the second round. Figueroa rose on shaky legs and Lipinets (17-2-1, 13 KOs) moved in and inflicted more punishment, round after round until the bout was stopped.
Lipinets was initially penciled in to perform on the non-televised portion of the undercard but was shifted to the main event when former four-time champion Adrien Broner withdrew from the matchup with Figueroa, citing mental health issues.
“I had a good fighter in front of me,” Lipinets said in the ring afterward. “My hat’s off to Omar for being a warrior. The punch that rocked Omar is the punch that my trainer and I have been working on for a long time. He came at me, and it was the perfect time to use it. I was too focused on protecting myself.
“I was concerned about him answering my punches, but it was not my job to stop the fight. 140 is my weight. I came back. I’m back.”