Wimbledon hero Johanna Konta's former coach from Weybridge has praised his former charge's 'knockout power' and the mental strength that has become her 'absolute weapon'.

Justin Sherring, who runs Weybridge Tennis Academy, first coached Johanna Konta when she was 19.

And today the 26-year-old plays Venus Williams on Centre Court in the Wimbledon semi-finals, an achievement that has not been matched since Virginia Wade in 1977.

Mr Sherring, who has attended all of Konta’s Wimbledon matches this year, said: “It’s fantastic. I actually think her tennis has improved during the tournament. It’s some of the best I’ve ever seen her play.”

“The actual first time I first saw her was when she was seventeen. I thought what great fun, she was really enthusiastic, bubbly and animated.

“Wow, what a really cool kid and just a couple years later I was responsible for her day to day work.”

Mr Sherring said that it wasn’t Konta’s tennis that initially stood out but rather her “enthusiastic personality”.

He added: “At 17, 18 and 19 you’re far from the finished product. If you want to develop and have passion you will get better. She’s 26 now and she continues to improve, not many players improve that much at that age.”

After Konta’s victory against second seed Simona Halep this week she is now on the verge of being the first British woman to reach a Wimbledon single’s final in 40 years.

First she will have to defeat Venus Williams in today's semi-final.

“She can beat anybody,” Mr Sherring said.

“Her mental strength was questioned and now it’s her absolute weapon, she’s eye balling the best players in world, she’s calling them out.

“She has knockout power in both hands right until the final bell.”

Mr Sherring acknowledged that he was “nervous” ahead of today’s semi-final but “really excited” to watch his former player from the Centre Court stands.

“I just don’t want it to be over like Andy Murray losing. You have to wait another year for this, the Australian Open is nice but Wimbledon is the holy grail.

"She has lifted the country, everyone is so interested and amazed by her performance. Two more matches please!”

He added that he sees Konta making history and defeating Williams today as he believes the American tennis legend won’t be able to cover the court as well as Konta’s last opponent.