- World rankings
Watson and Robson reach top 50
Watson, 20, will head to Melbourne for the year's first Grand Slam ranked 47th, with 18-year-old Robson up to 50th - career-high rankings for both Britons.
Not since 1987, when Jo Durie and Sara Gomer the British No. 1 and No. 2, has the nation had two women ranked among the world's top 50 at the same time.
Watson has targeted a place in the world top 20 in 2013 after becoming the first British woman to win a WTA singles title in 25 years with victory at the Japan Open in October.
Robson has risen 81 places since the start of the 2012 season, helped by her run to the fourth round of the US Open in September.
However Watson - who broke into the top 50 for the first time in 2012 - faces a race against time to be fit for the Australian Open, which begins on 14 January after pulling out of her final warm-up event with an elbow injury.
Watson pulled out of this week's final warm-up event, the Moorilla Hobart International, after straining her elbow in Auckland. Robson lost in the first round in Hobart to American Sloane Stephens.
Durie was ranked as high as No. 5 in the world and was a semi-finalist at the French and US Opens in 1983, while Gomer's reached a career-high ranking of No. 46.
Women's rankings: 1. Victoria Azarenka (BLR), 2. Maria Sharapova (RUS), 3. Serena Williams (USA), 4. Agnieszka Radwanska (POL), 5. Angelique Kerber (GER), 6. Li Na (CHN), 7. Sara Errani (ITA), 8. Petra Kvitova (CZE), 9. Sam Stosur (AUS), 10. Caroline Wozniacki (DEN)
Men's rankings: 1. Novak Djokovic (SRB), 2. Roger Federer (SWI), 3. Andy Murray (GBR), 4. Rafael Nadal (SPA), 5. David Ferrer (SPA), 6. Tomas Berdych (CZE), 7. Juan Martin Del Potro (ARG), 8. Jo-Wilfried Tsonga (FRA), 9. Janko Tipsarevic (SRB), 10. Richard Gasquet (FRA)