Great Britain's Elena Baltacha has moved up eight places to 50 in the latest world rankings.
The British number one reached the second round of all four Grand Slam tournaments and picked up her tenth career title during the recently-concluded 2011 season.
After learning of her rise up the standings, the 28-year-old described the previous 12 months as "the best" of her career.
"This has definitely been the best year of my career, no question, even better than 2010," Baltacha told reporters.
She later tweeted: "So chuffed to be the first British player since Jo Durie in the 1980s to make Top 50 2nd year running."
Baltacha's highest ranking is 49, a feat she achieved in September 2010.
