Great Britain has two female tennis players ranked in the top 50 for the first time since 1987.
Teenage sensation Laura Robson's first-round win at the Shenzhen Open last week propelled her to 50th place, with compatriot Heather Watson already occupying 47th.
Jo Durie and Sara Gomer were the last pair to achieve the feat, which is seen as further indication of the rise of British tennis following Andy Murray's first Grand Slam win at the US Open.
Robson and Murray competed together at the London Olympics together in the mixed doubles pairing - seizing silver medals - and the 18-year-old former Wimbledon Girls champion was also in good form at Flushing Meadows in reaching the fourth round.
That fourth round appearance eclipsed Watson's efforts at last year's Wimbledon, where she battled to round three before falling to eventual runner-up Agnieszka Radwanska.