Forget Laura Robson, Johanna Konta is the tennis ace that got got away from Australia.

Sydney-born Konta shocked Wimbledon finalist Garbine Muguruza 7-6 (7-4) 6-7 (4-7) 6-2 in the longest women’s match in US Open history on Thursday to extend her remarkable winning streak to 15 matches.

But unlike when she played in the juniors at Flushing Meadows, Konta is no longer representing Australia.

After calling Collaroy on Sydney’s northern beaches home until she was 13, the 24-year-old now plays for Great Britain, just like Melbourne-born former Wimbledon junior champion Laura Robson.

“I left because my parents felt that the travel was just too long back and forth from Australia and we wanted to find a base in Europe,” Konta told AAP.

“I was training in Spain for 15 months and while I was there my parents didn’t want to be halfway around the world away from their 14-year-old daughter.

“So they migrated to the UK because they had Hungarian passports and that’s in the EU, so they could work there.”

Konta said her original plan was to stay in Spain but when “things didn’t work out” she moved back in with her folks in Britain.

A decade on, though, and Konta credits her Spanish coaches – as well an unshakeable belief in her ability – for her dramatic surge.

Unbeaten since Wimbledon, Konta isn’t counting and says she knows her run can’t last forever.

But she certainly gives herself a shot of toppling German 18th seed Andrea Petkovic on Saturday to make the second week of a grand slam for the first time.

“Every opponent is a new opponent. Trust me, they don’t give a crap how many matches I have won,” Konta said after her three-hour, 23-minute epic against ninth-seeded Muguruza.

“Obviously I’m happy that I have been able to stay healthy enough to be competing as much as I have.

“I am going to lose sooner or later. I’m not invincible. I’m no Serena Williams.

“I’m very humbled about this experience and just really enjoying every second of it.

“I’m also ambitious and I’m by no means content.”