Lulu Sun used to lose confidence in herself when she was beaten but now she's "flying", her coach says.
Sun beat Britain's Emma Radacanu on Monday to become the first New Zealand woman to reach the singles quarter-finals at the tournament.
Coach Vladimir Platenik said Sun was playing well in previous, smaller tournaments, but lost close matches to competitors who were "fighting to survive" and to get into the top 100 rank.
Those players were very tough to beat, and Sun would struggle to believe in herself herself when she was beaten in games or points.
"It was quite important that right now she understood that if she wants to compete with the best players in the world, she needs to play every point, no matter if she's winning the point or losing she always needs to focus on the next point.
"It's nothing new, it's just very difficult for for the players because you know, they know that every mistake, every bad decision, is very costly."
Her self belief grew after work on technique, fitness and most importantly the mental side of the game.
"She managed this very well, and also I think that with the winning of the matches and and beating the top players, you know she start to believe that she can do it."
In women's tennis, "everybody can beat everybody right now", he said.
"I was really happy that she qualified actually because it was not easy. And then from there I think Lulu is flying."
They were well prepared for the Wimbledon Centre Court crowd supporting British favourite Raducanu in the fourth round.
"You know Lulu was actually saying it's nothing compared to the French crowd.
"I think the crowd was good and you know obviously they were cheering for Emma a little bit more but they were very fair and then the atmosphere was great.
'Its going to be aggressive tennis'
Looking ahead to the quarter-final against Donna Vekic, he said the Croatian was very experienced and is playing aggressively.
"Probably it's going to be very aggressive tennis from both sides.
"I don't want to reveal too much of tactics, but obviously we're going to prepare for for the match and and try to to take this one as well."
Dwight Grieve, a competitive runner who lives in Te Anau and knows Sun and her family, said it had been amazing to witness her success.
"I am just so stoked for Lulu for what she's doing now, just watching her before on the screen after her win crying- it even put a tear in my eye just watching it, it's just awesome," he said.
Grieve said it was inspiring for young players.
"Lulu and her sister they've both supported the local tennis club here. In speaking to her she's always been a Kiwi... She's very proud of the fact she came from Te Anau," he said.
"We've got quite a strong tennis culture within the town... it'll help inspire others to come through, and there's a lot of people talking about how she's going and I mean it just proves, you can punch above your weight from wee towns in rural provinces and that sort of stuff. You can do anything you like, you can make it."
This sentiment was echoed by Southland mayor Rob Scott.
"It's really putting Te Anau Tennis Club on the map. It's really good for Southland and New Zealand and Te Anau, It's a small little town that can celebrate some really great success," Scott said.