Kimiko Date turned 40 yesterday and continues to amaze the world of tennis. She turned professional in March 1989. A little Japanese giant conqueror among (giant) young tennis pros.
She came back after a 12 year layoff ('96) in 2008, and has since beaten the best in tennis, won several ITF titles, and a WTA Tour title. This year she's won against Dinara Safina (twice), Nadia Petrova, Maria Sharapova, and Daniela Hantuchova (second time since '09) - all highly ranked players, and younger by more than a decade.
Take that, teen prodigies! (And where are any these days, btw).