Konta had no idea she had reached that significant mark in her career which has seen her surge into the world's top 10 and also could not remember who had been her first "scalp" in 2007.
It was the first time Barty had played Konta, who moved closer to a first WTA title on home soil.
The world number eight, 26, won 6-3 7-5 after converting her fourth match point against the 21-year-old.
She explained: "The grass court season is a great period for all us Brits and I love the fact that I drive to Eastbourne and Wimbledon and not have to get on a plane to travel to the tournament".
After holding her next serve Konta looked determined to finish the job, taking a 30-15 lead in what ought to have been the final game of the second set, before Barty found a way back in with some well-placed returns. Konta, though, regained her stranglehold on the game, winning five of the next six games to close... I get to stay at home for both of those tournaments and it is a lucky position to be in. "I had to raise my game and only had one little dip", she said.
"It was definitely a nice little comeback", she added.
She will continue to sharpen her game with a Saturday semi-final in Nottingham against Magdalena Rybarikova who beat American qualifier Kristie Ahn. "I worked very hard to get myself back into that second set and stop Ashleigh from running away with it".
The British number one will face either Donna Vekic or Maria Sakkari in the last four.