US Open 2015: Jo Konta relishing pressure at Flushing Meadows

Konta's previous best run at any Grand Slam was when she reached the second round at Flushing Meadows in 2012

Britain's Jo Konta puts her surprise US Open run down to being able to enjoy the pressure after working on the mental side of her game.

Konta beat 18th seed Andrea Petkovic 7-6 (7-2) 6-3 to reach round four, after converting her sixth match point.

Konta, ranked 97th, had previously won just one Grand Slam main-draw match.

"I think the main thing is I'm just really enjoying the situation, even when I lost I don't know how many match points," said Konta.

"I spoke to my mum after on the phone. My dad was going on about tennis and my mum was like, 'Oh, you embrace this whole opportunity, this whole scenario that you got to experience, because, you know, that's what life is about, experiences'."

Britain's Fed Cup captain Judy Murray had described how Konta was suffering from "performance anxiety" when she lost a poor match against Belarus in February.

The 24-year-old, on a 16-match winning run, has since been working with London-based "mental coach" Juan Coto, and has had four top-10 wins in the last three months.

"I don't necessarily feel any different," said Konta.

"I think I have developed better and better habits of the initial things that I bring into my mind when things don't go my way.

"I think maybe that has got a bit better and more routine."

Konta's poise on court has been notable, as she has come through six matches in qualifying and the main draw in New York - something she says is "a work in progress".

"I am an entertainer of sorts, so I want to present an image that I would like," she added.

"This is no secret. I'm not the calmest or the most, like, really cool person out there.

"Everyone knows that I can be quite bubbly and I can be quite emotional."

Petkovic (left) reached the quarter-finals of the US Open in 2011

Konta will play two-time Wimbledon champion and fourth seed Petra Kvitova in the last 16 on Monday, with the opportunity to become Britain's first female Grand Slam quarter-finalist since Jo Durie in 1984.

'I'm really looking forward to the challenge," said Konta. "I have never played her. I have obviously seen her play.

"A two-time Grand Slam champion - I'm feeling pretty lucky that I get an opportunity to play against such a player."