Emma Raducanu retires from Wimbledon with breathing issues

British teenager Emma Raducanu became one of the stunning positive stories of Wimbledon by notching three surprising victories after she only made her WTA tour debut in June. 

As Raz Mirza explained for Sky Sports, however, Raducanu retired from her fourth-round match against Ajla Tomljanovic on Monday after she visibly struggled with her breathing. 

Raducanu dropped the opening set 4-6 and then lost the first three games of the second set before she requested a medical timeout after she appeared to be hyperventilating. The 18-year-old received medical attention after the match was called, but Sky Sports and BBC Sport noted there was no update on her condition as of late Monday afternoon ET. 

"I'm actually really shocked. Emma must be really hurt if she retired," Tomljanovic remarked in her post-match interview, per Kathleen McNamee of ESPN. 

"To play as a Brit at home, it is unbelievable. I'm really sorry for her as I wish we could have finished it. It's sport and I'm really wishing her all the best. 

"I think the beginning was really nervous on both sides, but by the end of that first set we were both playing really good tennis." 

Raducanu was the last British player in the women's and men's singles tournaments before Monday's developments. She's ranked No. 338 in the world.