By Nate Williams
Natasha Jonas suffered the first defeat of her professional career after succumbing to a fourth round stoppage against Viviane Obenauf at the Ice Arena in Cardiff.
Obenauf (13-4, 7 KOs) fought Jonas’ former Great Britain podium squad team mate Chantelle Cameron in her last fight in December, where she was forced to retire in the sixth round, but she wouldn’t quit in a determined effort against Jonas, who slumps to 6-1 (5 KOs) and hands over her WBA international super-featherweight strap.
Jonas, known as ‘Miss GB’ from her time on the British Olympic squad in 2012, shrugged off an awkward but aggressive attack from Obenauf in a fast-paced first round.
The Brazilian charged forward and bullied the Briton into the ropes with a series of swings, which had some effect, despite not many of those punches landing clean, in the opening two rounds.
However, Obenauf fired with much more success in the third as the two wrestled in what was turning into a brawl.
The fighting in a phone booth style favoured the 31-year-old Obenauf as Jonas slipped under a relentless barrage before falling a second time onto the seat of her pants following a ramrod left hook.
Another sharp left floored Jonas in the fourth and she couldn’t cope as she was dazed after a combination of ruthless, thudding blows that forced trainer Joe Gallagher to throw in the towel.
Anthony Sims Jr. opened his new contract with Matchroom with a fourth round stoppage win against Stanislav Eschner (10-10-1, 6 KOs) to extend his unbeaten professional record to 15 wins.
“I feel great because I've signed with the biggest promoter in the business and tonight was a great experience,” said the former number one US amateur.
The opening round was tentative from the 23-year-old light-heavyweight as he poked out his jab and launched an occasional attack to the body.
Sims Jr. revved up the action in the second as he caught Eschner with a bruising cross right hand before the 29-year-old Czech crumbled under pressure from a barrage against the ropes and took a knee for an eight count.
Floyd Mayweather’s cousin continued to dictate the pace in the third and in the fourth, he found his opening for victory with a left hook that wobbled Eschner, forcing him to cover up in the corner.
However, after solid right on the chin, referee Martin Williams stopped the contest at 1:13 in the round.