Johanna Konta has moved up to No 18 in the women's world ranking, making her the first British female to enter the top 20 for 33 years.
The Sydney-born 25-year-old's position is largely due to her semi-final appearance at this season's Grand Slam event in Australia.
She also reached the last eight of two other hard court tournaments, in Miami and Monterey, earlier this year, which followed on from a successful autumn during which she made it to the last 16 at the US Open.
Although Konta is yet to win a tournament on the main WTA Tour, she has tasted success 11 times on the ITF circuit.
And her position in the ranking could rise further when she competes in the North American hard court events later this year, on her favourite surface.
Konta celebrated her rise up the ranking, from 21 last week, by winning her first round match at the Aegon Open in Nottingham. Seeded No 2, Konta beat American Victoria Duval 6-3 6-0.
The last British woman to reach the top 20 was Jo Durie in 1983 - she climbed up to No 5 in the world a year later.
The Bristol-born player won two WTA Tour events in 1983, the same year she reached the semi-finals of the French and US Opens.
"It's kind of an interesting one. It's strange how the ranking system works," she said.
"It's funny to see how I have moved up in the rankings and didn't get any points in the last tournament. It's a nice thing to see but I am very much focused on being here in Nottingham this week."
In that momentous season, she was a quarter-finalist in Australia, while reaching the same stage at Wimbledon in 1984.
Two other Brits are ranked inside the top 100, with Heather Watson at 56 and Naomi Broady (81).
At the top end of the list, Serena Williams remains at No 1 ahead of the player she lost to in Saturday's final at Roland Garros - Spaniard Garbine Muguruza.
Meanwhile, in the men's game, Andy Murray remains at No 2 behind Novak Djokovic. The second highest ranked British male is Aljaz Bedene who has moved eight spots up the list to No 58.
Kyle Edmund at No 84 and Dan Evans (93) are other Brits inside the top 100.